JP7708477B2 - Satellite positioning device, satellite positioning method, and program - Google Patents

Description

The present disclosure relates to a satellite positioning device and a satellite positioning method for performing satellite positioning,
This concerns the programs to achieve these goals.

In order to perform satellite positioning with high accuracy, error factors such as (1) orbital error of the positioning satellite (artificial satellite), (2) clock error of the positioning satellite, (3) delay due to the ionosphere, (4) delay due to the troposphere, (5) signal shielding, and (6) multipath must be taken into consideration.

In particular, in urban areas with many skyscrapers and mountainous areas with thick trees, error factors such as (5) and (6) described above have a large effect, making highly accurate satellite positioning difficult.

As a related technique, Patent Literature 1 discloses a position measurement device capable of acquiring position information accurately and continuously. The position measurement device performs a first position identification process to acquire a current position and its error range by performing satellite positioning, and a second position identification process to acquire the current position by using a physical quantity measurement value, corrects the correspondence between the current position and the physical quantity acquired by the second position identification process when the error range satisfies a predetermined accuracy condition, and acquires the result of the corrected second position identification process when acquiring the current position.

The error range is calculated based on the positioning accuracy obtained by combining the reception conditions for each position of a plurality of positioning satellites, and the deviation of the obtained current position from the predicted position according to the movement status of the own aircraft.

JP 2019-060619 A

However, in the position measuring device of Patent Document 1, satellite positioning can be realized when there are four or more visible satellites that can receive signals (radio waves) from positioning satellites, but satellite positioning cannot be realized when the number of visible satellites is three or less due to the effect of signal obstruction described above (5).

One example of an objective of the present disclosure is to continuously perform highly accurate satellite positioning even when signal blocking occurs.

In order to achieve the above object, a satellite positioning device according to one aspect of the present disclosure includes:
a receiving unit that receives a positioning signal transmitted from each of the positioning satellites;
a generation unit that generates first accumulated information by associating, for each reception date and time information indicating a reception date and time when the positioning signal was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and stores the first accumulated information in a storage device;
a correction unit that, when an abnormality exists in the current observation information, refers to the first accumulated information, generates corrected observation information for correcting the current observation information having an abnormality based on past observation information stored before the present time of the positioning satellite corresponding to the current observation information having an abnormality, and corrects the current observation information having an abnormality in the first accumulated information to the corrected observation information;
The present invention is characterized by having the following.

In order to achieve the above object, a satellite positioning method according to one aspect of the present disclosure includes:
The computer
generating accumulated information by associating, for each piece of reception date and time information indicating a date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the accumulated information in a storage device;
When an abnormality is found in the current observation information, referring to the first accumulated information, and generating corrected observation information for correcting the current observation information having an abnormality based on past observation information stored before the present time of the positioning satellite corresponding to the current observation information having an abnormality, and correcting the current observation information having an abnormality in the first accumulated information to the corrected observation information;
The present invention is characterized by having the following.

Furthermore, in order to achieve the above object, a program according to one aspect of the present disclosure includes:
generating accumulated information by associating, for each piece of reception date and time information indicating a date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the accumulated information in a storage device;
When an abnormality is found in the current observation information, referring to the first accumulated information, and generating corrected observation information for correcting the current observation information having an abnormality based on past observation information stored before the present time of the positioning satellite corresponding to the current observation information having an abnormality, and correcting the current observation information having an abnormality in the first accumulated information to the corrected observation information;
The method includes instructions for executing the method.

As described above, according to the present disclosure, even if signal blocking occurs, it is possible to continuously perform highly accurate satellite positioning.

FIG. 1 is a diagram for explaining an example of a satellite positioning device included in a satellite positioning system. FIG. 2 is a diagram for explaining an example of a data structure of accumulated information (for observation information). FIG. 3 is a diagram for explaining signal shielding. FIG. 4 is a diagram for explaining a method for correcting abnormal observation information. FIG. 5 is a diagram for explaining a method for correcting abnormal observation information. FIG. 6 is a diagram for explaining the bias in the arrangement of positioning satellites. FIG. 7 is a diagram for explaining accumulated information when the positioning satellites are unevenly positioned. FIG. 8 is a diagram for explaining an example of the data structure of the stored information (for satellite position information). FIG. 9 is a diagram for explaining an example of the operation of the satellite positioning device. FIG. 10 is a diagram illustrating an example of a computer that realizes the satellite positioning device according to the embodiment.

First, an overview will be given to facilitate understanding of the embodiments described below.
A satellite positioning device (user segment) is a device that measures the current position of the satellite positioning device using multiple positioning satellites (space segments). The satellite positioning device is mounted on, for example, a vehicle, an aircraft, a ship, a mobile device, etc.

In the current satellite positioning system, when there are four or more visible satellites, the satellite positioning device can perform accurate satellite positioning (normal).

However, when the number of visible satellites decreases due to the above-mentioned (5) signal obstruction, and the number of visible satellites falls to three or less, satellite positioning becomes impossible. For example, in urban areas, mountainous areas, and the like, when radio waves are blocked by obstructions (e.g., buildings, trees, etc.) and the number of visible satellites falls to three or less, satellite positioning becomes impossible.

In addition, even if there are four or more visible satellites, if the observation information (observation data) described below contains abnormalities due to the influence of multipath described above (6), the accuracy of the satellite positioning calculated using the observation information will decrease.

Furthermore, (7) even if the number of visible satellites is four or more, in urban areas, the visible satellites for satellite positioning are concentrated near the zenith, resulting in a bias in the placement of positioning satellites in the sky, which reduces the accuracy of satellite positioning.

Through this process, the inventors discovered a problem in which accurate satellite positioning is not possible when (5) signal blocking occurs, or (6) multipath occurs, or (7) there is a bias in the placement of positioning satellites, and they also came up with a means for solving the problem.

In other words, the inventor has come up with a means for enabling continuous, highly accurate satellite positioning even when (5) signal blocking occurs, or (6) multipath occurs, or (7) bias occurs in the positioning satellite arrangement.

Hereinafter, an embodiment will be described with reference to the drawings. In the drawings described below, elements having the same or corresponding functions are denoted by the same reference numerals, and repeated description thereof may be omitted.

(Embodiment)
The configurations of a satellite positioning system and a satellite positioning device in an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining an example of a satellite positioning device included in the satellite positioning system.

[System configuration]
1 includes positioning satellites 30 (30a, 30b, 30c, 30d, and 30e) and a satellite positioning device 10. The number of positioning satellites 30 is not limited to five.

The satellite positioning system may be, for example, a Global Navigation Satellite System (GNSS), etc. Specifically, the satellite positioning system calculates the current position of the satellite positioning device 10 based on positioning signals transmitted from each of the positioning satellites 30.

The satellite positioning device 10 receives positioning signals from the positioning satellites 30, and generates observation information based on the received positioning signals. Thereafter, the satellite positioning device 10 calculates the current position based on the generated observation information.

The satellite positioning device 10 provides information indicating the calculated current position to various applications, such as a navigation system and an automatic driving system.

The satellite positioning device 10 is, for example, an information processing device such as a CPU (Central Processing Unit), a programmable device such as an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or a circuit, computer, mobile terminal, or the like equipped with any one or more of these.

The storage device 20 is a database, a server computer, a circuit having a memory, etc. The storage device 20 stores, for example, at least accumulated information, which will be described later. In the example of Fig. 1, the storage device 20 is provided outside the satellite positioning device 10, but may be provided inside the satellite positioning device 10.

The positioning satellite 30 revolves around a predetermined satellite orbit at a predetermined orbital period, and transmits a positioning signal that is phase-modulated with data indicating the transmission date and time.

[Device configuration]
A detailed description will be given of the satellite positioning device 10. In the example of Fig. 1, the satellite positioning device 10 includes a receiving unit 11, a generating unit 12, a correcting unit 13, and an estimating unit 14.

In satellite positioning, the satellite positioning device 10 calculates the current position using observation information (pseudo-range information, carrier phase information) and positioning satellite position information.

Positioning methods that require the positions of positioning satellites include, for example, point positioning, realtime kinematic (RTK) positioning, and precise point positioning (PPP) positioning.

The receiver 11 receives the positioning signals transmitted from the respective positioning satellites, and generates observation information (pseudo distance information, carrier phase information) and positioning satellite position information based on the received positioning signals. Specifically, the positioning signal receiver 21 has an antenna 11a for receiving the positioning signals, a circuit for demodulating the positioning signals, and the like.

A case where there is an abnormality in the observation information (pseudo distance information, carrier phase information) will be explained.
The generation unit 12 generates accumulated information (first accumulated information) by associating the reception date and time information representing the date and time when the positioning signal was received with the observation information corresponding to each positioning satellite at the reception date and time, and stores the information in the storage device 20.

The reception date and time information is, for example, information indicating the date and time when the positioning signal was received. The observation information includes pseudo-range information indicating a pseudo-range, or carrier phase information indicating a carrier phase, or both of these.

2 is a diagram for explaining an example of the data structure of the accumulated information (for observation information). In FIG. 2, accumulated information 101 and 102 are shown as an example of accumulated information 100 (first accumulated information).

The accumulated information 101 is information in which pseudo-distance information corresponding to each of the positioning satellites 30a, 30b, 30c, 30d, and 30e is associated with each of the times T1, T2, T3, etc. indicated by the reception date and time information. In the example of Fig. 2, for convenience of explanation, the pseudo-distance information is represented by symbols such as La11 to La13, etc., Lb11 to Lb13, etc., Lc11 to Lc13, etc., Ld11 to Ld13, etc., Le11 to Le13, etc.

The accumulated information 102 is information in which carrier phase information corresponding to each of the positioning satellites 30a, 30b, 30c, 30d, and 30e is associated with each of the times T1, T2, T3, and so on indicated by the reception date and time information. In the example of Fig. 2, for convenience of explanation, the carrier phase information is represented by symbols such as Pa11 to Pa13, and so on, Pb11 to Pb13, and so on.

When there is an abnormality in the observation information at the current time, the correction unit 13 refers to the accumulated information 100, and generates corrected observation information for correcting the abnormal current observation information based on past observation information stored before the current time of the positioning satellite 30 corresponding to the abnormal observation information at the current time. Then, the correction unit 13 corrects (changes) the abnormal current observation information in the accumulated information 100 to the corrected observation information.

Anomalies in the observation information occur, for example, when (5) signal blocking occurs, or (6) multipath occurs, or (7) there is a bias in the positioning satellite arrangement.

(5) What happens when signal blocking occurs?
When signal blocking occurs, the positioning signal cannot be received, and therefore observation information (pseudorange information, or carrier phase information, or both) cannot be obtained.

When the correcting unit 13 is unable to obtain the current observation information, it determines that the current observation information is abnormal. This will be described in detail with reference to Figs.

Fig. 3 is a diagram for explaining signal blocking. In the example of Fig. 3, a vehicle 40 (mobile body) equipped with a satellite positioning device 10 is moving. The satellite positioning device 10 of the vehicle 40 receives positioning signals from each of the four positioning satellites 30a, 30b, 30c, and 30d at times T1 and T2 (normal).

In contrast, at time T3, the positioning signal from the positioning satellite 30d is blocked by the building 50, and the satellite positioning device 10 of the vehicle 40 cannot receive the positioning signal from the positioning satellite 30d (abnormal). However, even at time T3, the satellite positioning device 10 of the vehicle 40 can receive the positioning signals from each of the three positioning satellites 30a, 30b, and 30c.

Fig. 4 is a diagram for explaining a method for correcting abnormal observation information. In the example of Fig. 4, the pseudorange of the L1 signal band is expressed by a simple numerical value for easy understanding. In the case of dual frequency positioning, accumulated information of signal bands of two frequencies is generated, and pseudorange information of the two frequencies is used.

The accumulated information 101a shown in FIG. 4A indicates that the pseudorange information of the positioning satellite 30d could not be acquired at time T3 due to the influence of signal blocking (anomalous pseudorange information "-").

When the pseudorange information cannot be acquired, the modifying unit 13 modifies the pseudorange information having an anomaly. That is, when the observation information has an anomaly, the modifying unit 13 generates modified observation information in order to modify the observation information having an anomaly. Then, the modifying unit 13 modifies (changes) the observation information having an anomaly to the modified observation information.

The corrected observation information can be calculated, for example, by any one of the following methods (A), (B), (C), or (D).

In method (A), observation information from the positioning satellite corresponding to the observation information containing an anomaly is obtained at a point in time (t1) one moment before the current point in time (t0) and a point in time two moments before that (t2), and corrected observation information is generated based on equation 1.

(Equation 1)
f1(t0)=f(t1)+(f(t1)-f(t2))

f1(t0): Corrected observation information f(t1): Observation information at the time (t1) one point before the current time (t0) f(t2): Observation information at the time (t2) two points before the current time (t0)

In the example of Figure 4, corrected observation information "7" is generated based on pseudorange information "6" and "5" for time points T1 (corresponding to t1) and T2 (corresponding to t2) stored before time point T3 (corresponding to t0) for positioning satellite 30d in accumulated information 101a.

Then, as shown in accumulated information 101b in FIG. 4B, the abnormal pseudo distance information "-" is corrected (changed) to corrected observation information "7" (corrected pseudo distance information).

In method (B), observation information from two past points (observation information from the point (t1) one point before the current point (t0) and the point two points before that (t2)) is obtained, a linear function (Equation 2) is generated, and corrected observation information is generated using the generated linear function.

(Equation 2)
f2(t0)=a×t0+b

f2(t0): Corrected observation information a: Slope (f(t2)-f(t1)/t2-t1)
b: Intercept

In method (C), observation information for three past points (observation information for the point in time (t1) one point prior to the current point in time (t0), the point in time two points prior to the current point in time (t2), and the point in time three points prior to the current point in time (t3)) is obtained, a quadratic function (Equation 3) is generated, and corrected observation information is generated using the generated quadratic function.

(Equation 3)
f3(t0)=a×t0 ² +b×t0+c

f3(t0): Corrected observation information a: Real-valued constant (≠0)
b: A real-valued constant c: A real-valued constant

In method (D), corrected observation information is generated by the least squares method using observation information from a plurality of past points (observation information from one or more points prior to the current time (t0)).

In addition, as with the accumulated information for pseudo-distance information described above, if there is an abnormality in the accumulated information for carrier phase information, corrected observation information (corrected carrier phase information) is generated and the abnormal carrier phase information is corrected (changed) to the corrected observation information.

In addition, in the example of the stored information 101b in FIG. 4, the observation information containing an anomaly is overwritten with the corrected observation information, but this overwriting is not necessary.

Moreover, the pre-correction accumulated information and the corrected accumulated information may be stored separately in the storage device 20. Specifically, the pre-correction accumulated information 101a and the corrected accumulated information 101b in FIG.

(6) What happens when multipath occurs?
When multipath occurs, the observed information (pseudorange information, or carrier phase information, or both) becomes an abnormal value (outlier).

The correcting unit 13 determines that the current observation information is abnormal if the change in the current observation information from the past observation information is equal to or greater than a preset threshold value. This will be described in detail with reference to FIG.

The threshold may be determined, for example, based on past observation information affected by multipath, or may be determined by experiments, simulations, etc. Regarding the threshold, a threshold for pseudo-range information and a threshold for carrier phase information are prepared for each of the pseudo-range information and the carrier phase information.

Fig. 5 is a diagram for explaining a method for correcting abnormal observation information. In the example of Fig. 5, the pseudorange of the L1 signal band is expressed by a simple numerical value for easy understanding. In the case of dual frequency positioning, accumulated information of signal bands of two frequencies is generated, and pseudorange information of the two frequencies is used.

The accumulated information 101c shown in FIG. 5A indicates that the pseudorange information of the positioning satellite 30a at time T5 has become an abnormal value due to the influence of multipath (abnormal pseudorange information "12").

5, the threshold is set to 4 or more. Therefore, the current pseudorange information has changed by 4 or more from the pseudorange information immediately before the current time point, and the current pseudorange information is an abnormal value.

When the pseudorange information is an abnormal value, the correction unit 13 corrects the abnormal pseudorange information. That is, when the observation information is abnormal, the correction unit 13 generates corrected observation information in order to correct the abnormal observation information.

The corrected observation information can be calculated, for example, by any one of the methods (A), (B), (C), or (D) described above.

In the example of Figure 5, method (A) is used to generate corrected observation information "6" based on pseudorange information "7" and "8" for time points T1 (corresponding to t1) and T2 (corresponding to t2) of positioning satellite 30a in accumulated information 101c stored before time point T5 (corresponding to t0).

Then, as shown in accumulated information 101d in FIG. 5B, the abnormal pseudo-range information "12" is corrected (changed) to corrected observation information "6" (corrected pseudo-range information).

In addition, in the example of the stored information 101d in FIG. 5, the observation information containing an anomaly is overwritten with the corrected observation information, but this overwriting is not necessary.

In addition, the uncorrected accumulated information and the corrected accumulated information may be stored separately in the storage device 20. Specifically, the uncorrected accumulated information 101c and the corrected accumulated information 101d in FIG.

(7) A case where a bias occurs in the arrangement of positioning satellites will be described.
6 is a diagram for explaining the bias of the arrangement of positioning satellites. (5) Although a positioning satellite 30d cannot receive the positioning signal due to the influence of signal blocking, there is another visible satellite 30e (positioning satellite) from which the positioning signal can be received.

However, blocking the signal of the only positioning satellite 30d in a different direction causes a bias in the arrangement of satellites available for positioning, and the accuracy of satellite positioning decreases. For example, if the positioning satellite 30a is in the northeast, the positioning satellite 30b is in the east, the positioning satellite 30c is in the southeast, the positioning satellite 30d is in the west, and the positioning satellite 30e is in the east, then if only the positioning satellite 30d is blocked, there will be no positioning satellites in the west, and the positioning satellites will be biased to the east, which will decrease the accuracy of satellite positioning.

Therefore, even if the correction unit 13 can switch to another visible satellite 30e, it generates corrected observation information for the positioning satellite 30d using one of the methods (A), (B), (C), or (D) described above for a predetermined period of time.

The preset period is a period during which the accuracy of satellite positioning does not decrease, and may be determined, for example, through experiments or simulations.

Fig. 7 is a diagram for explaining the accumulated information when the positioning satellites are unevenly positioned. In the accumulated information 101e in Fig. 7, at time points T5 and T6, the observation information (pseudo distance information) of the positioning satellite 30c can no longer be acquired, but the positioning signal of the visible satellite 30e can still be received.

However, in the stored information 101f in Fig. 7, no other observation information (pseudo distance information) of the visible satellite 30e is used, and the corrected observation information "5", "5" of the positioning satellite 30d is continued to be used. Note that the example in Fig. 7 shows that at time T7 (within the period), normal observation information of the positioning satellite 30d became available.

In an embodiment, even if there is an abnormality in the observation information at the current time, i.e., (5) signal blocking has occurred, or (6) there is a multipath effect, or (7) there is a bias in the positioning satellite arrangement, the abnormal observation information can be corrected based on past observation information stored before the current time, thereby enabling continuous, highly accurate satellite positioning.

A case where there is an abnormality in the positioning satellite position information will be explained.
The generating unit 12 generates accumulated information (second accumulated information) by associating the positioning satellite position information with each piece of reception date and time information, and stores the information in the storage device 20 .

When there is an abnormality in the current positioning satellite position information, the correction unit 13 first refers to the accumulated information (second accumulated information) and generates corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality based on past positioning satellite position information stored before the present time for the positioning satellite 30 corresponding to the current positioning satellite position information having an abnormality.

Next, the correction unit 13 corrects the current positioning satellite position information at which the abnormality exists in the stored information (second stored information) to corrected positioning satellite position information.

Fig. 8 is a diagram for explaining an example of the data structure of the accumulated information (for satellite position information). The accumulated information 201a shown in Fig. 8A is information in which satellite position information corresponding to each of the positioning satellites 30a, 30b, 30c, 30d, and 30e is associated with each of the times T1, T2, T3, ... represented by the reception date and time information. The satellite position information is information represented by three-dimensional coordinates.

In the accumulated information 201a shown in A of Figure 8, due to the effects of (5), (6), and (7) described above, there were abnormalities in the observation information at time T5 for positioning satellite 30a, at times T6 and T7 for positioning satellite 30c, and at times T8 and T9 for positioning satellite 30e, and therefore abnormalities occurred in the satellite position information.

That is, the accumulated information 201a shown in A of Figure 8 indicates that an abnormality has occurred in the satellite position information "30, 10, 42" for positioning satellite 30a at time T5, an abnormality has occurred in the satellite position information "-" for positioning satellite 30c at times T6 and T7, and an abnormality has occurred in the satellite position information "-" for positioning satellite 30e at times T7, T8, and T9.

Therefore, when there is an abnormality in the satellite position information, the correction unit 13 corrects the abnormal satellite position information. Specifically, when there is an abnormality in the satellite position information, the correction unit 13 generates corrected satellite position information (X', Y', Z') for correcting each of the three-dimensional coordinates (X, Y, Z) of the abnormal satellite position information.

The satellite position information is determined to be abnormal when (5) the satellite position information cannot be obtained due to the effects of signal obstruction, or (6) the change in the current satellite position information compared to the past satellite position information due to the effects of multipath is greater than or equal to a predetermined threshold.

The threshold value may be determined, for example, based on satellite position information that has been affected by past multipath, or may be determined through experiments, simulations, or the like.

Each of the three-dimensional coordinates of the corrected satellite position information can be calculated, for example, by one of the following methods (A'), (B'), (C'), and (D').

In method (A'), satellite position information for the positioning satellite corresponding to the abnormal satellite position information is obtained at the point in time (t1) one point in time prior to the current point in time (t0) and the point in time two points in time prior to the current point in time (t2), and corrected satellite position information (three-dimensional coordinates (X', Y', Z') respectively) is generated based on equation 1'.

(Number 1')
g1(t0)=g(t1)+(g(t1)-g(t2))

g1 (t0): Corrected satellite position information (three-dimensional coordinates)
g(t1): Satellite position information at the time (t1) one point before the current time (t0) g(t2): Satellite position information at the time (t2) two points before the current time (t0)

At time T5 of the positioning satellite 30a in the accumulated information 201a shown in A of Figure 8, corrected satellite position information "11, 36, 13" is generated based on the satellite position information "11, 35, 13" and "11, 34, 13" of times T4 (corresponding to t1) and T3 (corresponding to t2) stored before time T5 (corresponding to t0) of the positioning satellite 30a.

Then, as shown in the accumulated information 201b in FIG. 8B, the abnormal satellite position information "30, 10, 42" is corrected (changed) to corrected satellite position information "11, 36, 13."

Also, for the abnormal satellite position information "-" of positioning satellite 30c at time points T6 and T7, method (A') is used to generate corrected satellite position information "30, 32, 15" and "30, 34, 15." For the abnormal satellite position information "-" of positioning satellite 30e at time points T7, T8, and T9, method (A') is used to generate corrected satellite position information "38, 60, 40," "36, 60, 40," and "34, 60, 40."

In method (B'), satellite position information for two past points (satellite position information for the point (t1) one point prior to the current point (t0) and the point (t2) before that) is obtained, a linear function (equation 2') is generated, and corrected satellite position information (three-dimensional coordinates) is generated using the generated linear function.

(Number 2')
g2(t0)=a×t0+b

g2 (t0): Corrected satellite position information (three-dimensional coordinates)
a: slope (g(t2)-g(t1)/t2-t1)
b: Intercept

In method (C'), satellite position information for three past points (satellite position information for the point in time (t1) prior to the current point in time (t0), the point in time two points prior to the current point in time (t2), and the point in time three points prior to the current point in time (t3)) is obtained, a quadratic function (equation 3') is generated, and corrected satellite position information is generated using the generated quadratic function.

(Number 3')
g3(t0)=a×t0 ² +b×t0+c

g3 (t0): Corrected satellite position information (three-dimensional coordinates)
a: real-valued constant (≠ 0)
b: A real-valued constant c: A real-valued constant

In the method (D'), corrected satellite position information is generated by the least squares method using satellite position information of a plurality of past points (satellite position information at one or more points prior to the current time (t0)).

The estimation unit 14 executes a satellite positioning process for calculating the current position using the observation information and satellite position information of each positioning satellite included in the currently stored information, and estimates the current position.

In addition, in the example of the stored information 201b in FIG. 8, the satellite position information having an abnormality is overwritten with the corrected satellite position information, but this overwriting is not necessary.

Moreover, the pre-correction accumulated information and the corrected accumulated information may be stored separately in the storage device 20. Specifically, the pre-correction accumulated information 201a and the corrected accumulated information 201b in FIG. 8 may be stored separately in the storage device 20.

The estimation unit 14 executes a satellite positioning process to calculate the current position using the observation information of each positioning satellite 30 and the positioning satellite position information at the current time, and estimates the current position.

In an embodiment, even if there is an abnormality in the satellite position information at the current time, i.e., (5) signal blocking has occurred, or (6) there is a multipath effect, or (7) there is a bias in the positioning satellite arrangement, the abnormal satellite position information is corrected based on past satellite position information stored before the current time, so that accurate satellite positioning can be continued.

In an open sky environment, even if a visible satellite moves into a range with an elevation angle of 0 degrees or less and becomes invisible, satellite positioning processing is performed for a preset period using correction information for the invisible satellite.

[Device operation]
Next, the operation of the satellite positioning device in the embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining an example of the operation of the satellite positioning device. In the following description, the diagram will be referred to as appropriate. Also, in the embodiment, a satellite positioning method is implemented by operating the satellite positioning device. Therefore, the description of the satellite positioning method in the embodiment will be replaced with the following description of the operation of the satellite positioning device.

As shown in FIG. 9, first, the receiver 11 receives the positioning signals transmitted from each of the positioning satellites 30, and generates observation information (pseudo-distance information, carrier phase information) and positioning satellite position information based on the received positioning signals (step A1).

Next, for each piece of reception date and time information indicating the date and time at which the positioning signal was received, the generation unit 12 generates accumulated information (first accumulated information) by associating the reception date and time information with observation information (pseudo distance information, carrier phase information) corresponding to each positioning satellite at the reception date and time, and stores the information in the memory device 20 (step A2).

In step A2, accumulated information (second accumulated information) is generated for each piece of reception date and time information in association with positioning satellite position information indicating the position of each positioning satellite, and is stored in the storage device 20.

Next, if there is no abnormality in the observation information and the positioning satellite position information at the current time (step A3: No), the correction unit 13 proceeds to step A5 and executes the satellite positioning process. Also, if there is an abnormality in the pseudorange information, the carrier phase information, or the positioning satellite position information, or any two or more of them at the current time (step A3: Yes), the correction unit 13 proceeds to step A4 and generates corrected observation information and corrected positioning satellite position information for the information with the abnormality.

In step A3, (5) when signal blocking occurs and the current pseudorange information, carrier phase information, or positioning satellite position information cannot be acquired, the correction unit 13 determines that an abnormality has occurred.

In step A3, the correction unit 13 (6) determines that the current observation information is abnormal if the change in the current observation information from the past observation information is equal to or greater than a preset threshold value when multipath occurs. The abnormality in the pseudorange information is determined using the change in the pseudorange information and a threshold value for the pseudorange information. The abnormality in the carrier phase information is determined using the change in the carrier phase information and a threshold value for the carrier phase information.

Also, in step A3, (6) when multipath occurs, if the change in the current positioning satellite position information relative to the past positioning satellite position information is equal to or greater than a predetermined threshold (threshold for positioning satellite position information), the correction unit 13 determines that the current positioning satellite position information is abnormal.

Next, if there is an abnormality in the observation information (pseudorange information, or carrier phase information, or both) at the current time, the correction unit 13 refers to the first accumulated information and generates corrected observation information for correcting the observation information with an abnormality based on past observation information stored before the current time of the positioning satellite 30 corresponding to the observation information with an abnormality at the current time (step A4).

Specifically, in step A4, the corrector 13 generates corrected observation information by any one of the above-mentioned methods (A), (B), (C), and (D). Then, in step A4, the corrector 13 corrects (changes) the observation information containing the abnormality to the corrected observation information.

Also, in step A4, if there is an abnormality in the positioning satellite position information at the current time, the correction unit 13 refers to the second accumulated information and generates corrected positioning satellite position information for correcting the abnormal positioning satellite position information based on past positioning satellite position information stored before the current time of the positioning satellite 30 corresponding to the positioning satellite position information that has an abnormality at the current time.

Specifically, in step A4, the correction unit 13 generates corrected positioning satellite position information by any one of the above-mentioned methods (A'), (B'), (C'), and (D'). Then, in step A4, the correction unit 13 corrects (changes) the abnormal positioning satellite position information to the corrected positioning satellite position information.

The estimation unit 14 performs satellite positioning processing to calculate the current position using the observation information of each positioning satellite and the positioning satellite position information contained in the current accumulated information (first accumulated information, second accumulated information), and estimates the current position (step A5).

In this manner, the satellite positioning device 10 repeatedly executes the processes of steps A1 to A5 described above.

[Effects of the embodiment]
According to the embodiment, even if there is an abnormality in the observation information at the current time, i.e., (5) signal blocking has occurred, or (6) there is a multipath effect, or (7) there is a bias in the positioning satellite arrangement, the abnormal observation information is corrected based on past observation information stored before the current time, thereby enabling continuous, highly accurate satellite positioning.

[program]
The program in the embodiment may be a program that causes a computer to execute steps A1 to A5 shown in Fig. 9. By installing and executing this program in a computer, the satellite positioning device and the satellite positioning method in the embodiment can be realized. In this case, the processor of the computer functions as a receiving unit 11, a generating unit 12, a correcting unit 13, and an estimating unit 14 and performs processing.

The program in the embodiment may be executed by a computer system constructed by a plurality of computers. In this case, for example, each computer may function as any one of the receiving unit 11, the generating unit 12, the modifying unit 13, and the estimating unit 14.

[Physical configuration]
Here, a computer that realizes the satellite positioning device by executing a program in the embodiment will be described with reference to Fig. 10. Fig. 10 is a diagram showing an example of a computer that realizes the satellite positioning device in the embodiment.

As shown in FIG. 10, a computer 110 includes a CPU (Central Processing Unit) 1
The computer 110 includes a CPU 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader/writer 116, and a communication interface 117. These components are connected to each other via a bus 121 so as to be able to communicate data with each other. Note that the computer 110 may include a GPU or an FPGA in addition to the CPU 111 or instead of the CPU 111.

The CPU 111 loads the programs (codes) in the embodiment stored in the storage device 113 into the main memory 112 and executes them in a predetermined order to perform various calculations. The main memory 112 is typically a volatile storage device such as a dynamic random access memory (DRAM). The programs in the embodiment are provided in a state stored in a computer-readable recording medium 120. The programs in the embodiment may be distributed on the Internet connected via the communication interface 117. The recording medium 120 is a non-volatile recording medium.

Specific examples of the storage device 113 include a hard disk drive and a semiconductor storage device such as a flash memory. The input interface 114 mediates data transmission between the CPU 111 and input devices 118 such as a keyboard and a mouse. The display controller 115 is connected to a display device 119 and controls the display on the display device 119.

The data reader/writer 116 mediates data transmission between the CPU 111 and the recording medium 120, reads programs from the recording medium 120, and writes processing results in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and other computers.

Specific examples of the recording medium 120 include CF (Compact Flash (registered trademark)) and S
Examples of suitable storage media include general-purpose semiconductor storage devices such as Secure Digital (SD), magnetic recording media such as flexible disks, and optical recording media such as compact disk read only memories (CD-ROMs).

The satellite positioning device in the embodiment can be realized by using hardware corresponding to each part, instead of a computer with a program installed. Furthermore, the satellite positioning device 10 may be realized in part by a program and the remaining part by hardware.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details within the scope of the invention.

[Additional Notes]
The following supplementary notes are further disclosed with respect to the above-described embodiments. A part or all of the above-described embodiments can be expressed by (Supplementary Note 1) to (Supplementary Note 21) described below, but are not limited to the following descriptions.

(Appendix 1)
a receiving unit that receives a positioning signal transmitted from each of the positioning satellites;
a generation unit that generates first accumulated information by associating, for each reception date and time information indicating a reception date and time when the positioning signal was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and stores the first accumulated information in a storage device;
a correction unit that, when an abnormality exists in the current observation information, refers to the first accumulated information, generates corrected observation information for correcting the current observation information having an abnormality based on past observation information stored before the present time of the positioning satellite corresponding to the current observation information having an abnormality, and corrects the current observation information having an abnormality in the first accumulated information to the corrected observation information;
A satellite positioning device having the above configuration.

(Appendix 2)
The satellite positioning device described in Appendix 1, wherein the correction unit determines that the current observation information is abnormal if the current observation information cannot be obtained or if a change in the current observation information relative to the past observation information is equal to or greater than a predetermined threshold.

(Appendix 3)
The satellite positioning device according to claim 2, wherein the observation information includes pseudo-range information indicating a pseudo-range, or carrier phase information indicating a carrier phase, or both of these pieces of information.

(Appendix 4)
The satellite positioning device according to claim 3, wherein when the pseudorange information is used, a standalone positioning process is executed as the satellite positioning process.

(Appendix 5)
The satellite positioning device according to claim 3, wherein, when the carrier wave phase information is used, a real-time kinematic positioning process is executed as the satellite positioning process.

(Appendix 6)
4. The satellite positioning device according to claim 3, wherein, when the pseudorange information and the carrier phase information are used, a precise point positioning process is executed as the satellite positioning process.

(Appendix 7)
the generating unit, when a positioning method requires positioning satellite position information indicating a position of the positioning satellite in the course of the satellite positioning process, generates second accumulated information by associating the positioning satellite position information with each of the reception date and time information, and stores the second accumulated information in the storage device;
the correction unit, when there is an abnormality in the current positioning satellite position information, refers to the second accumulated information, and generates corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality based on past positioning satellite position information stored before the present time of the positioning satellite corresponding to the current positioning satellite position information having an abnormality, and corrects the current positioning satellite position information having an abnormality in the second accumulated information to the corrected positioning satellite position information;
The satellite positioning device according to claim 1, wherein the estimation unit executes the satellite positioning process to calculate a current position using the observation information of each of the positioning satellites and the positioning satellite position information at the current time, and estimates the current position.

(Appendix 8)
The computer
generating first accumulated information by associating, for each piece of reception date and time information indicating a reception date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the first accumulated information in a storage device;
When an abnormality is found in the current observation information, the first accumulated information is referred to, and corrected observation information for correcting the current observation information having an abnormality is generated based on past observation information stored before the current time of the positioning satellite corresponding to the current observation information having an abnormality, and the current observation information having an abnormality in the first accumulated information is corrected to the corrected observation information.
Satellite positioning method.

(Appendix 9)
A satellite positioning method as described in Appendix 8, wherein the current observation information is determined to be abnormal if the current observation information cannot be obtained or if a change in the current observation information relative to the past observation information is equal to or greater than a predetermined threshold.

(Appendix 10)
The satellite positioning method according to claim 9, wherein the observation information includes pseudo-range information indicating a pseudo-range, or carrier phase information indicating a carrier phase, or both of these pieces of information.

(Appendix 11)
The satellite positioning method according to claim 10, wherein, when the pseudorange information is used, a standalone positioning process is executed as the satellite positioning process.

(Appendix 12)
The satellite positioning method according to claim 10, further comprising: executing a real-time kinematic positioning process as the satellite positioning process when the carrier phase information is used.

(Appendix 13)
The satellite positioning method according to claim 10, wherein, when the pseudorange information and the carrier phase information are used, a precise point positioning process is executed as the satellite positioning process.

(Appendix 14)
In the case where the positioning method requires positioning satellite position information indicating the position of the positioning satellite in the satellite positioning process, the positioning satellite position information is associated with each of the reception date and time information to generate second accumulated information, and the second accumulated information is stored in the storage device;
When the current positioning satellite position information has an abnormality, the second accumulated information is referred to, and corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality is generated based on past positioning satellite position information stored before the current time of the positioning satellite corresponding to the current positioning satellite position information having an abnormality, and the current positioning satellite position information having an abnormality in the second accumulated information is corrected to the corrected positioning satellite position information;
The satellite positioning method according to claim 8, further comprising: executing the satellite positioning process for calculating a current position using observation information of each of the positioning satellites and positioning satellite position information at the current time, thereby estimating a current position.

(Appendix 15)
On the computer,
generating first accumulated information by associating, for each piece of reception date and time information indicating a reception date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the first accumulated information in a storage device;
When an abnormality is found in the current observation information, the first accumulated information is referred to, and corrected observation information for correcting the current observation information having an abnormality is generated based on past observation information stored before the current time of the positioning satellite corresponding to the current observation information having an abnormality, and the current observation information having an abnormality in the first accumulated information is corrected to the corrected observation information.
A program containing instructions.

(Appendix 16)
The program described in Appendix 15, further comprising: determining that the current observation information is abnormal if the current observation information cannot be obtained or if a change in the current observation information relative to the past observation information is equal to or greater than a predetermined threshold value .

(Appendix 17)
The program according to claim 16, wherein the observation information includes pseudo-range information representing a pseudo-range, or carrier phase information representing a carrier phase, or both of these pieces of information.

(Appendix 18)
The program according to claim 17, further comprising: a step of executing a point-based positioning process as a satellite positioning process when the pseudorange information is used.

(Appendix 19)
The program according to claim 17, further comprising: a program for executing a real-time kinematic positioning process as a satellite positioning process when the carrier phase information is used.

(Appendix 20)
18. The program according to claim 17, further comprising: a program for executing a precise point positioning process as a satellite positioning process when the pseudorange information and the carrier phase information are used.

(Appendix 21)
In the case where the positioning method requires positioning satellite position information indicating the position of the positioning satellite in the satellite positioning process, the second accumulated information is generated by associating the positioning satellite position information with each of the reception date and time information, and the second accumulated information is stored in the storage device;
When the current positioning satellite position information has an abnormality, the second accumulated information is referred to, and corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality is generated based on past positioning satellite position information stored before the current time of the positioning satellite corresponding to the current positioning satellite position information having an abnormality, and the current positioning satellite position information having an abnormality in the second accumulated information is corrected to the corrected positioning satellite position information;
The program according to claim 15, further comprising: executing the satellite positioning process to calculate a current position using observation information of each of the positioning satellites and positioning satellite position information at the current time, thereby estimating a current position.

Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

This application claims priority based on Japanese Patent Application No. 2022-088159, filed on May 31, 2022, the disclosure of which is incorporated herein in its entirety.

According to the above description, even if (5) signal blocking occurs, or (6) there is an effect of multipath, or (7) there is a bias in the arrangement of positioning satellites, it is possible to continuously perform highly accurate satellite positioning. Also, it is useful in fields where highly accurate satellite positioning is required.

REFERENCE SIGNS LIST 10 Satellite positioning device 11 Receiving unit 11a Antenna 12 Generating unit 13 Correcting unit 14 Estimating unit 20 Storage device 30, 30a, 30b, 30c, 30d, 30e Positioning satellite 40 Vehicle 50 Building 110 Computer 111 CPU
112 Main memory 113 Storage device 114 Input interface 115 Display controller 116 Data reader/writer 117 Communication interface 118 Input device 119 Display device 120 Recording medium 121 Bus

Claims (15)

A receiving means for receiving a positioning signal transmitted from each of the positioning satellites;
a generating means for generating first accumulated information by associating, for each piece of reception date and time information indicating a reception date and time when the positioning signal was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the first accumulated information in a storage device;
a correction means for, when an abnormality exists in the current observation information, generating corrected observation information for correcting the current observation information having an abnormality based on past observation information stored before the present time of the positioning satellite corresponding to the current observation information having an abnormality by referring to the first accumulated information, and correcting the current observation information having an abnormality in the first accumulated information to the corrected observation information;
A satellite positioning device having the above configuration. The satellite positioning device of claim 1, wherein the correction means determines that the current observation information is abnormal when the current observation information cannot be obtained or when a change in the current observation information relative to the past observation information is equal to or greater than a predetermined threshold value. The satellite positioning device according to claim 2 , wherein the observation information includes pseudo-range information indicating a pseudo-range, or carrier phase information indicating a carrier phase, or both of these pieces of information. The satellite positioning device according to claim 3 , wherein when the pseudorange information is used, a point-only positioning process is executed as the satellite positioning process. The satellite positioning device according to claim 3 , wherein when the carrier wave phase information is used, a real-time kinematic positioning process is executed as the satellite positioning process. The satellite positioning device according to claim 3 , wherein when the pseudorange information and the carrier phase information are used, a precise point positioning process is executed as the satellite positioning process. the generating means, when a positioning method requires positioning satellite position information indicating the position of the positioning satellite in the satellite positioning process, generates second accumulated information by associating the positioning satellite position information with each of the reception date and time information, and stores the second accumulated information in the storage device;
the correction means, when there is an abnormality in the current positioning satellite position information, refers to the second accumulated information, and generates corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality based on past positioning satellite position information stored before the present time of the positioning satellite corresponding to the current positioning satellite position information having an abnormality, and corrects the current positioning satellite position information having an abnormality in the second accumulated information to the corrected positioning satellite position information;
The satellite positioning device according to claim 1 , wherein the estimation means executes the satellite positioning process to calculate a current position using observation information of each of the positioning satellites and positioning satellite position information at the current time, thereby estimating the current position. The computer
generating first accumulated information by associating, for each piece of reception date and time information indicating a reception date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the first accumulated information in a storage device;
When an abnormality is found in the current observation information, the first accumulated information is referred to, and corrected observation information for correcting the current observation information having an abnormality is generated based on past observation information stored before the current time of the positioning satellite corresponding to the current observation information having an abnormality, and the current observation information having an abnormality in the first accumulated information is corrected to the corrected observation information.
Satellite positioning method. The satellite positioning method according to claim 8, further comprising: determining that the current observation information is abnormal if the current observation information cannot be obtained or if a change in the current observation information relative to the past observation information is equal to or greater than a preset threshold value. The satellite positioning method according to claim 9 , wherein the observation information includes pseudo-range information indicating a pseudo-range, or carrier phase information indicating a carrier phase, or both of these pieces of information. The satellite positioning method according to claim 10 , further comprising the step of: executing a stand-alone positioning process as the satellite positioning process when the pseudorange information is used. The satellite positioning method according to claim 10 , further comprising the step of: executing a real-time kinematic positioning process as the satellite positioning process when the carrier wave phase information is used. The satellite positioning method according to claim 10 , further comprising the steps of: executing a precise point positioning process as the satellite positioning process when the pseudorange information and the carrier wave phase information are used. In the case where the positioning method requires positioning satellite position information indicating the position of the positioning satellite in the satellite positioning process, the positioning satellite position information is associated with each of the reception date and time information to generate second accumulated information, and the second accumulated information is stored in the storage device;
When the current positioning satellite position information has an abnormality, the second accumulated information is referred to, and corrected positioning satellite position information for correcting the current positioning satellite position information having an abnormality is generated based on past positioning satellite position information stored before the current time of the positioning satellite corresponding to the current positioning satellite position information having an abnormality, and the current positioning satellite position information having an abnormality in the second accumulated information is corrected to the corrected positioning satellite position information;
The satellite positioning method according to claim 8 , further comprising the steps of: executing the satellite positioning process for calculating a current position using observation information of each of the positioning satellites and positioning satellite position information at the current time, thereby estimating the current position. On the computer,
generating first accumulated information by associating, for each piece of reception date and time information indicating a reception date and time at which a positioning signal transmitted from each of the positioning satellites was received, the reception date and time information with observation information corresponding to each of the positioning satellites at the reception date and time, and storing the first accumulated information in a storage device;
When an abnormality is found in the current observation information, the first accumulated information is referred to, and corrected observation information for correcting the current observation information having an abnormality is generated based on past observation information stored before the current time of the positioning satellite corresponding to the current observation information having an abnormality, and the current observation information having an abnormality in the first accumulated information is corrected to the corrected observation information.
A program containing instructions.