JP7107820B2 - Positioning device, positioning method - Google Patents

Description

The present invention relates to a technology for selecting positioning signals (positioning satellites) used for positioning.

The device described in Patent Literature 1 includes a structure detection device such as a laser scanner or a stereo camera on a moving body. The device described in Patent Literature 1 sets an elevation mask using the positions of surrounding structures detected by a structure detection device. The device described in Patent Document 1 uses this elevation mask to limit the use of navigation signals from specific navigation satellites and performs positioning.

The device described in Patent Literature 2 includes a fisheye lens. The device described in Patent Literature 2 detects obstacles from the surrounding scenery detected by a fisheye lens. The device described in Patent Literature 2 sets the shielding area from the direction of the obstacle. The device described in Patent Document 2 performs positioning by restricting the use of radio waves from satellites in the direction of this shielded area.

JP 2017-15585 A Japanese Patent Application Laid-Open No. 2002-357422

However, as shown in Patent Document 1 and Patent Document 2, in the conventional configuration, in addition to the functional unit that outputs the data directly used for positioning, another device for setting the elevation mask and the shielding area must be used. not.

Therefore, an object of the present invention is to set a shielded area using data used for positioning.

A positioning device according to the present invention includes a satellite direction calculator, a distribution generator, and a shielded area setter. The satellite direction calculation unit uses the position of the positioning satellite in the NED coordinate system obtained from the navigation message superimposed on the positioning signal and the attitude angle of the positioning device obtained from the reception result of the positioning signal to calculate the position of the positioning satellite. Elevation and azimuth angles in the body coordinate system of the positioning device are calculated. The distribution generation unit generates a distribution of signal reception strength in the body coordinate system using the elevation angle and azimuth angle of the positioning satellite in the body coordinate system and the signal reception strength of the positioning signal. The shielded area setting unit uses the distribution in the body coordinate system to set a shielded area used for determining a positioning signal that has a low or zero influence on positioning.

With this configuration, the shielded area is set without using any functional units other than those used for positioning. Furthermore, by setting a shielded area in the body coordinate system, a shielded area caused by the own device (positioning device) and an object (for example, a moving body such as a ship) on which the own device is mounted is set.

According to this invention, the shielded area can be set using data used for positioning.

4 is a functional block diagram showing the configuration of a shielding information setting unit in the positioning device according to the first embodiment of the present invention; FIG. 1 is a functional block diagram showing the configuration of a positioning device according to a first embodiment of the present invention; FIG. (A), (B), and (C) are diagrams for explaining the concept of plotting the positions of positioning satellites in a sky plot in a body coordinate system. FIG. 10 is a diagram showing a concept of setting a shielding determination area in a sky plot; (A), (B), and (C) are diagrams showing an example of the concept of classification of projection points. It is a figure which shows an example of a signal level. (A) and (B) show an example of setting a shielded area. 4 is a flowchart showing main processing (positioning method) executed by the positioning device; 4 is a flowchart showing processing for calculating the direction of a positioning satellite; 9 is a flowchart showing processing for setting a shielded area; 1 is a functional block diagram showing the configuration of a positioning device using inertial sensors; FIG.

A positioning device and a positioning method according to a first embodiment of the present invention will be described with reference to the drawings. In the following description, a mobile object, especially a ship, is used as an object to which the positioning device is attached. The configuration of the present invention can be applied, and it can also be applied to stationary objects. However, the configuration of the present invention is more effective when the object is a moving object.

FIG. 1 is a functional block diagram showing the configuration of the shielding information setting section in the positioning device according to the embodiment of the present invention. FIG. 2 is a functional block diagram showing the configuration of the positioning device according to the embodiment of the present invention.

(Configuration of positioning device 10)
As shown in FIG. 2 , the positioning device 10 has a computing section 20 and an antenna device 30 . The antenna device 30 is connected to the computing section 20 .

Antenna device 30 is installed in a moving object to which positioning device 10 is attached. The antenna device 30 is composed of, for example, three or more GNSS antennas (not shown). Three or more GNSS antennas are not arranged such that all GNSS antennas are not aligned.

The three or more GNSS antennas respectively receive positioning signals transmitted from a plurality of positioning satellites (not shown) and output them to the computing section 20 .

A positioning signal (GNSS (Global Navigation Satellite Systems) signal) is a signal obtained by superimposing a PRN (Pseudo Random Noise) code and a navigation message on a carrier wave signal of a predetermined frequency. The PRN code is a code for identifying the positioning satellite of the transmission source. A navigation message is data including orbit information of a positioning satellite, correction information, and the like.

The computing unit 20 includes a positioning computing unit 21 and a shielding information setting unit 22 . The calculation unit 20 is, for example, a program that realizes the functions of the positioning calculation unit 21 and the shielding information setting unit 22, a storage unit that stores this program, and a calculation device such as a CPU that reads and executes this program from the storage unit. Realized. Alternatively, the arithmetic unit 20 is realized by an arithmetic element such as an IC that incorporates this program and executes this program.

The positioning signal is input to the positioning calculator 21 . The positioning calculator 21 observes the received signal strength (signal reception strength) SS for each positioning signal. The positioning calculation unit 21 acquires and tracks the code and carrier wave signal (carrier signal) for each positioning signal (positioning satellite) using a known method.

The positioning calculation unit 21 uses the code of the positioning signals received by the two or more GNSS antennas of the antenna device 30 and the tracking result of the carrier wave signal (for example, the carrier wave phase difference, the baseline vector, etc.) to determine the attitude from a known method. Angles (roll angle, pitch angle, yaw angle) R, P, Y are calculated. The position Psn is calculated in the NED coordinate system. At this time, the positioning calculation unit 21 calculates the posture angles R, P, and Y using the integrated value of the phase of the carrier wave signal. In this manner, the posture angles R, P, and Y are calculated with high accuracy by using the integrated value of the phase of the carrier wave signal.

In addition, the positioning calculation unit 21 uses a code tracking result (for example, code pseudorange etc.) of the positioning signal received by at least one GNSS antenna among the two or more GNSS antennas of the antenna device 30 to perform a known method. , the position Psn of the own device is calculated. In addition, the position Psn of the own device is calculated at the position of any one of the two or more GNSS antennas of the antenna device 30 or the geometric center position of the two or more GNSS antennas. When using any position of two or more GNSS antennas, the position Psn of the own device can be calculated by independent positioning using the positioning signal received by the GNSS antenna as the position Psn of the own device. Also, when using the geometric center positions of two or more GNSS antennas, the position Psn of the own device can be calculated by calculating the average value of the positioning results of each GNSS antenna.

The positioning calculation unit 21 demodulates the navigation message superimposed on the carrier wave signal based on the tracking result.

The positioning calculation unit 21 calculates the identification information SatN of the tracking satellite, the signal reception strength SS of the positioning signal from this positioning satellite, the position Psn of the device itself, the attitude angles R, P, Y of the device itself, and the navigation A message NM is output to the shielding information setting unit 22 . The positioning calculation unit 21 outputs necessary information among these pieces of information to various functional units (for example, a display image generation unit: not shown) connected after the positioning calculation unit 21 .

Schematically, the shielding information setting unit 22 sets a shielding area using various data used for positioning input from the positioning calculation unit 21 described above. A shielded area is an area set to discriminate positioning signals that are not used for positioning.

The shielding information setting section 22 outputs the shielding area to the positioning calculation section 21 . The positioning calculation unit 21 refers to the shielded area, and calculates the position Psn and the attitude angles R, P, and Y without using the positioning signals of the positioning satellites in the shielded area (zeroing the influence on the positioning). . In other words, the positioning calculator 21 selects positioning signals from positioning satellites outside the shielded area and calculates the position Psn and the attitude angles R, P, and Y. Thereby, the calculation accuracy of the position Psn and the attitude angles R, P, and Y is improved.

(Specific configuration of shielding information setting unit 22)
As shown in FIG. 1 , the shielding information setting unit 22 includes a satellite direction calculator 221 , a distribution generator 222 , and a shielded area setting unit 223 .

The position Psn, the attitude angles R, P, Y, the navigation message NM, and the identification information SatN of the positioning satellite are input to the satellite direction calculator 221 . In addition, the signal reception strength SS is input to the distribution generator 222 while being associated with the identification information SatN of the positioning satellite.

The satellite direction calculator 221 refers to the identification information SatN of the positioning satellite and extracts orbit information of the tracking satellite from the navigation message NM. The satellite direction calculator 221 uses this orbit information and the position Psn of the device itself to calculate the position PsatN of the positioning satellite with the position Psn of the device itself as the origin (center). The positioning satellite positions PsatN are obtained in the NED coordinate system.

The satellite direction calculator 221 uses the attitude angles R, P, and Y to calculate a conversion matrix. The conversion matrix is a matrix that performs coordinate conversion between the NED coordinate system based on the position of the device itself and the body coordinate system of the device itself. If the attitude angles R, P, and Y are known, the transformation matrix can be calculated by a known method.

The satellite direction calculation unit 221 calculates the elevation angle of the positioning satellite in the body coordinate system with the position of the device itself as the origin (center) using the position PsatN of the positioning satellite with the position of the device itself as the origin and the conversion matrix. Φb and azimuth angle θb are calculated. This calculation can be realized by a known geometric calculation formula. The satellite direction calculator 221 calculates elevation angles Φb and azimuth angles θb for a plurality of tracking satellites, preferably all tracking satellites. This process is not limited to once for one positioning satellite, but is performed multiple times for one positioning satellite, that is, over a predetermined length of time.

The satellite direction calculation unit 221 outputs the elevation angle Φb and the azimuth angle θb of the positioning satellite being tracked to the distribution generation unit 222 in association with the identification information SatN of the positioning satellite being tracked.

The distribution generator 222 generates a skyplot 800 in the body coordinate system. FIGS. 3(A), 3(B), and 3(C) are diagrams for explaining the concept of plotting the positions of the positioning satellites in the sky plot in the body coordinate system.

As shown in FIGS. 3(A), 3(B), and 3(C), the sky plot 800 is a hemispherical area COb on the zenith side defined by the body coordinate system centering on the position of the apparatus itself. , is two-dimensionally projected onto the reference plane (the plane that forms the bottom of the hemisphere) RP in the body coordinate system. The skyplot 800 has an elevation angle Φb set in the outward radial direction and an azimuth angle θb set in the circumferential direction, centered on the position of the device itself. The elevation angle Φb is 90° at the center of the skyplot 800 and decreases away from the center. For example, as shown in FIG. 3A, the azimuth angle θb is 360 degrees in one revolution, with a specific direction (for example, the direction toward the bow with respect to the center of the hull 90 as a reference) being θb=0° with respect to the center. °.

As shown in FIG. 3A, a sky plot 800 plots projection points 811B, 811C, 812B, and 812C of each positioning satellite. These projection points 811B, 811C, 812B, 812C are plotted by the positioning satellite elevation angle Φb and azimuth angle θb obtained in the body coordinate system described above.

For example, the projection point 811B is the elevation angle Φb and the azimuth angle in the body coordinate system of the positioning satellite SAT1 in the posture (Pitch=0°) of the hull (mobile body on which the positioning device 10 is mounted) 90 shown in FIG. Plotted by θb. On the other hand, the projection point 811C is plotted by the elevation angle Φb and the azimuth angle θb in the body coordinate system of the positioning satellite SAT1 at the attitude (Pitch=5°) of the hull 90 shown in FIG. 3(C).

Also, the projection point 812B is plotted by the elevation angle Φb and the azimuth angle θb in the body coordinate system of the positioning satellite SAT2 at the attitude (Pitch=0°) of the hull 90 shown in FIG. 3(B). On the other hand, the projection point 812C is plotted by the elevation angle Φb and the azimuth angle θb in the body coordinate system of the positioning satellite SAT2 at the attitude (Pitch=5°) of the hull 90 shown in FIG. 3(C).

Since the elevation angle Φb and the azimuth angle θb are calculated in the body coordinate system, the attitude of the hull 90 is not constant as shown in FIGS. However, the direction of each positioning satellite is accurately plotted on the sky plot with the hull 90 as the reference (center).

3(A), 3(B), and 3(C) show the case where the pitch angle (Pitch) changes, but the roll angle (Roll) and the yaw angle (Yaw) change. In this case, the directions (projection points) of the positioning satellites are also accurately plotted on the sky plot 800 of the body coordinate system.

The distribution generator 222 plots projection points on the sky plot 800 for all positioning satellites for which elevation angles Φb and azimuth angles θb have been calculated. If the elevation angle Φb and the azimuth angle θb are obtained at a plurality of times, the distribution generator 222 plots using the elevation angle Φb and the azimuth angle θb at each of the plurality of times. At this time, the distribution generator 222 associates each projection point on the sky plot 800 with the received signal strength SS.

The distribution generation section 222 outputs the sky plot 800 to the shielded area setting section 223 .

The shielded area setting unit 223 sets the shielded area from the sky plot 800 associated with the signal reception strength SS. Specifically, for example, the shielded area setting unit 223 sets the shielded area by the following method.

The shielding area setting unit 223 divides the entire area of the sky plot 800 into a plurality of shielding determination areas aij, as shown in FIG. FIG. 4 is a diagram showing the concept of setting the shielding determination area in the sky plot.

As shown in FIG. 4, the skyplot 800 is divided into multiple regions using the elevation angle Φb. Furthermore, the skyplot 800 is divided into multiple regions using the azimuth angle θb. A region divided by the elevation angle Φb and the azimuth angle θb is a shielding determination region aij.

For example, in the example of FIG. 4, the skyplot 800 is divided into regions each having an elevation angle Φb of 18° between 0° and 90°. Further, the skyplot 800 is divided into regions each having a range of azimuth angles θb of 30° between 0° and 360°. That is, a range of 18° in the elevation angle Φb and a range of 30° in the azimuth angle θb becomes the shielding determination area aij. The shielding judgment area aij can be identified by i (=1, 2, . . . ) in the direction of the elevation angle Φb, and j (=1, 2, . ).

The shielding area setting unit 223 classifies all projection points plotted on the sky plot 800 in units of shielding determination areas aij. FIGS. 5A, 5B, and 5C are diagrams showing an example of the concept of classification of projection points. 5(A), 5(B), and 5(C), the hatched area indicates the shielding determination area aij where the signal reception strength SS is obtained, and the unhatched area is A shielding determination area aij in which no signal reception strength SS is obtained is shown.

As shown in FIGS. 5A and 5B, the shielding area setting unit 223 refers to the identification information SatN of the positioning satellites, and refers to the positioning satellites SAT1 to SATm (m is an integer of 2 or more). The projection points are classified for each shielding determination area aij, and stored in association with the signal reception strength SS. As shown in FIG. 5B, when there are a plurality of projection points in one shielding determination area aij, the signal reception strengths SS of all these projection points are associated with the shielding determination area aij. and memorize it.

The shielded area setting unit 223 performs a process of classifying (associating) the projection points and the signal reception strengths SS with the shielding determination areas aij for all the positioning satellites. As a result, the shielding area setting unit 223 obtains a distribution in which the signal reception strength SS is associated with each shielding determination area aij, as shown in FIG. 5(C).

The shielding area setting unit 223 sets a representative value of the signal reception strength SS for each shielding determination area aij. Specifically, when the number of signal reception strengths SS associated with the shielding determination area aij is one, the shielding area setting unit 223 sets the signal reception strength SS to the representative value of the signal reception strengths SS. . Further, when there are a plurality of signal reception strengths SS associated with the shielding determination area aij, the shielding region setting unit 223 sets the statistically calculated values of the plurality of signal reception strengths SS to a representative signal reception strength SS. set to a value. As the statistically calculated value, for example, one of an average value, a median value, and the like may be used.

The shielding area setting unit 223 sets the signal level for each shielding determination area aij from the representative value of the signal reception strength SS for each shielding determination area aij. FIG. 6 is a diagram showing an example of signal levels. As shown in FIG. 6, the shielded area setting unit 223 sets the signal level to a plurality of levels. Each signal level classifies the representative values of a plurality of signal reception strengths SS in stages according to the height, and the strength of the representative value of the signal reception strengths SS included in one signal level has a width. have. In the example of FIG. 6, the shielding area setting unit 223 sets six levels from Level0 to Level5. Level 0 is set when the signal reception strength SS cannot be obtained. Level1 to Level5 are set in descending order of the representative value of the signal reception strength SS according to the height of the representative value.

The shielded area setting unit 223 uses this signal level distribution to set a shielded area for each shielding determination area aij. FIGS. 7A and 7B show an example of setting of the shielded area. FIG. 7A shows a case where the shielding area is set for each elevation angle, and FIG. 7B shows a case where the shielding area is set for the entire area of the sky plot.

(When setting the shielding area for each elevation angle)
The shielded area setting unit 223 sets a shielded area for each elevation angle Φb. Specifically, the shielded area setting unit 223 sets the shielded area based on the relative difference in signal level with respect to a plurality of shielding determination areas aij which are at the same elevation angle Φb and are arranged in the direction of the azimuth angle θb. .

For example, if the distribution of signal levels is as shown in FIG. 6, as shown in FIG. area, and level 5 is not an occluded area. In the area where the elevation angle Φb is between 54° and 72°, the shielding area setting unit 223 determines that Level 3 and below is a shielding area, and Level 4 and above is not a shielding area. The shielding region setting unit 223 selects Level 2 for the region where the elevation angle Φb is between 36° and 54°, the region where the elevation angle Φb is between 18° and 36°, and the region where the elevation angle Φb is between 0° and 18°. It is assumed that the following areas are shielded areas, and the areas above level 3 are not shielded areas.

This determination criterion is an example and can be set as appropriate. Basically, it is conceivable that the higher the elevation angle Φb is, the higher the level used as the determination criterion for the shielded area is set.

(When setting the shielding area in the entire area)
The shielded area setting unit 223 sets the signal level of the shielded area determination reference. Then, the shielded area setting unit 223 determines that the shielding determination area aij having a signal level equal to or lower than the determination standard is a shielded area. Also, the shielded area setting unit 223 determines that the shielding determination area aij having a signal level higher than the determination criterion is not a shielded area.

For example, if the distribution of signal levels is as shown in FIG. 6 and the signal level as the criterion is Level 3, the shielded area setting unit 223 sets the shielded area as shown in FIG. 7B.

By performing such processing, the shielded area setting unit 223 can set the shielded area in the body coordinate system. Thereby, the shielded area setting unit 223 can set a shielded area that depends on the structure of the moving body on which the positioning device 10 is mounted.

With this configuration and processing, the shielded area setting unit 223 can set the shielded area using only the data used for positioning. That is, the positioning device 10 can set the shielded area without using a device that is not directly related to positioning, such as a fisheye lens, laser scanner, or stereo camera.

At this time, if the shielded area is set for each elevation angle Φb, the shielded area and the non-shielded area (area outside the shielded area) can be set for each elevation angle Φb. Therefore, it is possible to appropriately set an area that can be used for positioning and an area that cannot be used for positioning even in a low elevation angle Φb area in which the signal reception strength SS is often relatively low compared to a high elevation angle Φb area.

Further, in the case of setting the blocking area in the entire area, only positioning signals having a predetermined signal reception strength SS or higher can be used for positioning regardless of the elevation angle Φb.

Then, the shielded area is set in this way, and the positioning calculation unit 21 performs the positioning calculation without using the positioning signals of the positioning satellites existing in the shielded area, thereby improving the positioning accuracy. That is, the position Psn and attitude angles R, P, and Y of the device itself calculated by the positioning calculation unit 21 described above are highly accurate.

In the above description, the processing such as setting of the shielded area executed by the positioning device is realized by a plurality of functional units, but these processing may be programmed and executed. In this case, it can be realized by a storage unit that stores this program and an arithmetic device such as a CPU that reads and executes this program from the storage unit. In this case, the methods shown in FIGS. 8, 9 and 10 may be programmed and used. FIG. 8 is a flowchart showing main processing (positioning method) executed by the positioning device. FIG. 9 is a flowchart showing processing for calculating the direction of a positioning satellite. FIG. 10 is a flowchart showing processing for setting a shielded area. Since the specific contents of each process have been described above, the specific description thereof will be omitted.

As shown in FIG. 8, the calculation device calculates the direction of the positioning satellite in the body coordinate system from various information and data used for positioning calculation (S11). Specifically, as shown in FIG. 9, the computing device calculates the position of the positioning satellite in the NED coordinate system from the own device position obtained from the positioning signal and the navigation message (S111). The computing device calculates the NED coordinate system, the body coordinate system, and the transformation matrix from the attitude angle of the device itself obtained from the positioning signal (S112). The computing device calculates the elevation angle Φb and the azimuth angle θb of the positioning satellite in the body coordinate system from the position of the positioning satellite and the transformation matrix (S113).

As shown in FIG. 8, the computing device uses the elevation angle Φb and the azimuth angle θb to generate a sky plot, which is the distribution of the received signal strength SS (S12).

As shown in FIG. 8, the computing device uses the sky plot to set the shielded area (S13). Specifically, as shown in FIG. 10, the computing device divides the entire skyplot area into a plurality of shielding determination areas aij based on the elevation angle Φb and the azimuth angle θb (S31). The computing device sets a shielding area in units of shielding determination areas aij from the signal reception strengths SS of the plurality of shielding determination areas aij (S32).

As shown in FIG. 8, the calculation device uses the shielded area to select a positioning satellite (positioning signal) to be used for positioning (S14), and performs positioning calculation (S15).

In addition, in the above description, the aspect of using only the positioning signal for the positioning calculation has been shown. However, it is also possible to use the output of an inertial sensor such as an acceleration sensor or an angular velocity sensor. FIG. 11 is a functional block diagram showing the configuration of a positioning device using inertial sensors.

As shown in FIG. 11, the positioning device 10A includes a computing section 20A, an antenna device 30A, and an inertial sensor 40. As shown in FIG. The calculation unit 20A includes a positioning calculation unit 21A and a shielding information setting unit 22. FIG. Note that the configuration and processing of the shielding information setting unit 22 are as described above, and a description thereof will be omitted.

The antenna device 30A and the inertial sensor 40 are connected to the positioning calculation section 21A.

The antenna device 30A is composed of two or more GNSS antennas (not shown). The inertial sensor 40 includes an orthogonal triaxial acceleration sensor and an angular velocity sensor. The inertial sensor 40 outputs the measured acceleration and angular velocity to the positioning calculator 21A.

The positioning calculation unit 21A calculates the position Psn, the attitude angles R, P, and , Y are calculated. Also, the positioning calculation unit 21A demodulates the navigation message NM from the tracking result of the positioning signal.

Even in the mode using the antenna device 30A and the inertial sensor 40, the shielding area can be set in the same manner as in the mode using only the antenna device 30 described above.

In the above description, the shielded area setting unit 223 determines the shielded area based on discretely set signal levels. However, the shielded area setting unit 223 can also set the shielded area and the non-shielded area by directly using the representative value of the signal reception strength SS assigned to the shielding determination area aij. In this case, the shielded area setting unit 223 sets a threshold for the representative value, determines that it is a shielded area if it is equal to or less than the threshold, and determines that it is not a shielded area (is a non-shielded area) if it exceeds the threshold. Judge. In this case, the shielded area setting unit 223 may determine that the shielding determination area aij for which the signal reception strength SS is not obtained is a shielded area.

Also, in the above description, the shielding area is set in a state in which the entire area of the sky plot 800 is divided into a plurality of shielding determination areas aij. However, without setting the shielding determination area, the distribution of the signal reception strength SS may be used as it is to set the shielding area based on the magnitude difference of the signal reception strength SS.

Also, in the above description, a mode was shown in which the positioning signals of the positioning satellites existing within the shielded area are not used for the positioning calculation. However, the positioning signals of the positioning satellites present in the shielded area and the positioning signals of the positioning satellites not present in the shielded area may be weighted differently during the positioning calculation. Specifically, the positioning signals of positioning satellites that exist within the shielded area have less impact on the positioning accuracy (lower weighting), and the positioning signals of positioning satellites that do not exist in the shielded area have less impact on the positioning accuracy. Increase impact (increase weighting). As a result, for example, when the number of positioning satellites being tracked is small, it is possible to suppress the deterioration of the positioning accuracy due to these positioning signals while using the positioning signals of the positioning satellites existing in the shielded area.

Also, in the above description, both the elevation angle Φb and the azimuth angle θb are divided at regular angular intervals to set the shielding determination areas aij. However, these intervals need not be constant angular intervals. For example, with respect to the elevation angle Φb, the lower the angle, the wider the angle interval, or conversely, the lower the angle, the narrower the angle interval. Further, for example, regarding the azimuth angle θb, the angle interval may be widened as the bow side, that is, closer to θb=0°, and narrower as θb=180° is approached. Furthermore, in the first determination of the shielded area, the above determination may be performed by further dividing the shielded determination area aij in the vicinity of the azimuth angle θb, which is the boundary between the shielded area and the non-shielded area.

Also, in the above description, the manner in which the shielded area is determined using the signal reception strength SS has been described. However, the shielded area may be determined using the number of receptions of the positioning signal. Here, the number of receptions of the positioning signal means the number of receptions with signal reception strength that allows tracking.

Also, in the above description, the manner in which the shielding area is set according to the magnitude of the signal reception strength SS has been shown. However, it is also possible to set the shielding area based on the magnitude relationship of the variation in the signal reception strength SS. In this case, the area with the larger variation is set as the shielded area, and the area with the smaller variation is set as the non-shielded area.

Also, in the above description, the timing for setting the shielded area is not described in detail. The setting timing of the shielded area may be, for example, before the actual positioning calculation is started, that is, at the beginning of the use of the positioning device. Furthermore, the shielded area may be set at predetermined time intervals and fed back to the positioning calculation each time. Further, it is preferable to spend as long as possible the observation of the signal reception strength SS and the acquisition of the elevation angle Φb and the azimuth angle θb for setting the shielded area, that is, for generating the sky plot 800 . Thereby, the influence of shielding elements (shielding due to disturbance) existing outside the hull 90 can be suppressed.

10, 10A: Positioning devices 20, 20A: Calculation units 21, 21A: Positioning calculation unit 22: Shield information setting unit 30, 30A: Antenna device 40: Inertial sensor 90: Hull 221: Satellite direction calculation unit 222: Distribution generation unit 223 : Shielding area setting unit 800: Sky plots 811B, 811C, 812B, 812C: Projection point aij: Shielding determination area COb: Area of zenith side hemisphere defined by body coordinate system NM: Navigation messages SAT1, SAT2, SATm: Positioning satellite SatN: identification information SS: signal reception strength

Claims (16)

Using the position of the positioning satellite in the NED coordinate system obtained from the navigation message superimposed on the positioning signal and the attitude angle of the positioning device obtained from the reception result of the positioning signal, the position of the positioning satellite in the positioning device a satellite direction calculator that calculates elevation and azimuth angles in a body coordinate system;
a distribution generation unit that generates a distribution of the signal reception strength in the body coordinate system using the elevation angle and the azimuth angle of the positioning satellite in the body coordinate system and the signal reception strength of the positioning signal;
a shielded area setting unit that sets a shielded area used for determining a positioning signal that sets the influence on positioning to low or zero, using the distribution in the body coordinate system;
A positioning device. The positioning device according to claim 1,
The distribution generation unit
setting an entire area obtained by two-dimensionally projecting a hemispherical area on the zenith side defined by the body coordinate system centered on the positioning device onto a reference plane in the body coordinate system;
The shielding area setting unit
setting the shielding area using the distribution in the body coordinate system in the entire area;
Positioning device. The positioning device according to claim 2,
The shielding area setting unit
dividing the entire area into a plurality of shielding determination areas based on the elevation angle and the azimuth angle in the body coordinate system;
setting the shielding area in units of the plurality of shielding determination areas;
Positioning device. The positioning device according to claim 3,
The shielding area setting unit
setting the shielding region based on the magnitude of the signal reception intensity of the plurality of shielding determination regions aligned in the azimuth direction or the variation in the magnitude of the signal reception intensity for each elevation angle in the body coordinate system;
Positioning device. The positioning device according to claim 3,
The shielding area setting unit
setting the shielded region based on the magnitude of the signal reception intensity of the plurality of shielding determination regions in the entire region or the variation in the magnitude of the signal reception intensity;
Positioning device. The positioning device according to any one of claims 1 to 5,
Using carrier signals of the positioning signals received by a plurality of GNSS antennas, calculating an attitude angle of the positioning device, and using a code of the positioning signals received by at least one GNSS antenna of the plurality of GNSS antennas, A positioning calculation unit that calculates the position of the positioning device,
Positioning device. The positioning device according to claim 6,
The positioning calculation unit
calculating the attitude angle and the position by weighting the positioning signal of the positioning satellite differently depending on whether it is included in the shielded area set by the shielded area setting unit;
Positioning device. The positioning device according to claim 6 or claim 7,
The position of the positioning device is the position of any one of the plurality of GNSS antennas, or the geometric center position of the plurality of GNSS antennas.
Positioning device. Using the position of the positioning satellite in the NED coordinate system obtained from the navigation message superimposed on the positioning signal and the attitude angle of the positioning device obtained from the reception result of the positioning signal, the position of the positioning satellite in the positioning device Calculate the elevation and azimuth angles in the body coordinate system,
using the elevation angle and azimuth angle of the positioning satellite in the body coordinate system and the signal reception strength of the positioning signal to generate a distribution of the signal reception strength in the body coordinate system;
Using the distribution in the body coordinate system to set a shielded region used to determine a positioning signal that has a low or zero impact on positioning;
Positioning method. The positioning method according to claim 9,
setting an entire area obtained by two-dimensionally projecting a hemispherical area on the zenith side defined by the body coordinate system centered on the positioning device onto a reference plane in the body coordinate system;
setting the shielding area using the distribution in the body coordinate system in the entire area;
Positioning method. The positioning method according to claim 10,
dividing the entire area into a plurality of shielding determination areas based on the elevation angle and the azimuth angle in the body coordinate system;
setting the shielding area in units of the plurality of shielding determination areas;
Positioning method. The positioning method according to claim 11,
setting the shielded area based on the magnitude of the received signal intensity of the plurality of shielded determination areas arranged in the azimuth direction or the variation in the magnitude of the received signal strength for each elevation angle in the body coordinate system; . The positioning method according to claim 11,
setting the shielded region based on the magnitude of the signal reception intensity of the plurality of shielding determination regions in the entire region or the variation in the magnitude of the signal reception intensity;
Positioning method. The positioning method according to any one of claims 9 to 13,
Using carrier signals of the positioning signals received by a plurality of GNSS antennas, calculating an attitude angle of the positioning device, and using a code of the positioning signals received by at least one GNSS antenna of the plurality of GNSS antennas, calculating the position of the positioning device;
Positioning method. The positioning method according to claim 14,
calculating the attitude angle and the position by giving different weights to the positioning signals of the positioning satellites depending on whether they are included in the shielded area;
Positioning method. The positioning method according to claim 14 or 15,
The position of the positioning device is the position of any one of the plurality of GNSS antennas, or the geometric center position of the plurality of GNSS antennas.
Positioning method.

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