JP2024066324A - Mobile object positioning device and mobile object positioning method - Google Patents

Abstract

To realize a moving-body positioning device that has a simple configuration and determines whether or not a mobile station is in a stationary state without relying on the detection accuracy of an inertia sensor.SOLUTION: A moving-body positioning device 2 comprises: a satellite signal prediction section 26 that calculates satellite signal prediction information 19 including a satellite signal 10 received by a mobile station 29 and a satellite signal 10 prediction model to be distributed at the current time or in the future on the basis of a correction signal 11 based on the satellite signal 10 distributed from a base station 4; a satellite signal continuity determination section 27 that calculates satellite signal continuity information 16, which is information related to the continuity of the satellite signal 10 on the basis of the satellite signal 10 and the satellite signal prediction information 19; and a computation control section 28 that determines whether the mobile station 29 is in a stationary state on the basis of the satellite signal continuity information 16. When the continuity of the satellite signal 10 is detected on the basis of the satellite signal continuity information 16, the computation control section 28 determines that the mobile station 29 is in the stationary state.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mobile object positioning device and a mobile object positioning method.

Conventionally, there is known a technique for correcting errors in vehicle position detected by the Global Navigation Satellite System (GNSS), which performs positioning by receiving satellite signals transmitted to the Earth from artificial satellites positioned above the Earth.

Patent document 1 discloses a technology that integrates the detection positions of GNSS and an inertial sensor that detects the momentum and attitude changes of a moving body, as shown below.

"The maximum likelihood position at a first time point is calculated using the error variance values of the GNSS output position and the dead reckoning (DR) position, the relative position calculated by the DR device from the first time point to the second time point is added to the maximum likelihood position to calculate an assumed DR position, the relative position is added to the GNSS output position at the first time point to calculate an adaptive DR position, the difference between the GNSS output position and the adaptive DR position is obtained as an adaptive DR error, and the vehicle state at that time is also determined. The adaptive DR error according to the vehicle state is stored, and the average value and variance value of the adaptive DR error are updated by taking into account the newly calculated adaptive DR error, and if the GNSS output position is within a possible existence range obtained by adding an error ellipse centered on a position obtained by shifting the assumed DR position by the average value of the adaptive DR error to the error ellipse based on the assumed DR position, the maximum likelihood error ellipse is calculated based on that, or if not, based on the assumed DR position."
In the above-described vehicle position correction method, the vehicle position detected by the GNSS is corrected based on the vehicle position and attitude obtained by integrating the vehicle momentum and attitude change calculated from the measurement values obtained by the inertial sensor.

In this method, errors in the inertial sensors gradually accumulate as estimated errors in the vehicle position, so the measurement accuracy of the inertial sensors is extremely important and these inertial sensors need to be calibrated.

In addition, the calibration of the inertial sensor can be performed with high accuracy when the vehicle is stationary, allowing the error components to be clearly estimated.

Therefore, determining whether the vehicle is stationary is important for calibrating the inertial sensor, and Patent Document 2 discloses the following technology.

"A mobile object acceleration/distance estimation circuit comprising an acceleration estimation unit that inputs a moving object's acceleration signal in the traveling direction, determines whether the moving object is at rest based on a plurality of signals that detect the stationary state of the moving object, measures a bias value included in the moving object acceleration signal when the stationary state is determined, corrects the moving object acceleration signal using the measured bias value, and calculates and outputs an estimated acceleration and distance estimate of the moving object using the corrected moving object acceleration signal and the moving object speed estimate output by the scale factor/speed estimation unit."
Furthermore, Patent Document 3 discloses a technique in which "when an output signal input from a motion detector is within a threshold range, it is determined that a moving object is stationary."

These technologies can be used to determine when a vehicle is stationary.

Patent Publication No. 6900341 JP 2005-195395 A JP 2001-242192 A

According to the technology described in Patent Document 2, multiple sensors are used to determine whether the vehicle is stationary.

However, when using multiple sensors, the complexity of the vehicle's onboard equipment configuration becomes an issue.

In addition, according to the technology described in Patent Document 3, the stationary state is determined based on the amount of momentum and the magnitude of posture change detected by the inertial sensor.

However, when using an inertial sensor with low detection accuracy, there is the problem that the accuracy of determining the stationary state is also low.

The object of the present invention is to realize a mobile object positioning device and a mobile object positioning method that are simple in configuration and can determine the stationary state of a mobile station (a mobile object equipped with a GNSS antenna) without relying on the detection accuracy of an inertial sensor.

To achieve the above objective, the present invention is configured as follows:

A mobile positioning device includes a satellite signal prediction unit that calculates satellite signal prediction information including a satellite signal received by a mobile station and a prediction model of the satellite signal to be distributed at the current time or in the future based on a correction signal based on the satellite signal distributed from a base station, a satellite signal continuity determination unit that calculates satellite signal continuity information, which is information regarding the continuity of the satellite signal, based on the satellite signal and the satellite signal prediction information, and a calculation control unit that determines the stationary state of the mobile station based on the satellite signal continuity information, and when the calculation control unit detects the continuity of the satellite signal based on the satellite signal continuity information, it determines that the mobile station is stationary.

In addition, in a mobile positioning method, satellite signal prediction information is calculated that includes a satellite signal received by a mobile station and a prediction model of the satellite signal to be distributed at the current time or in the future based on a correction signal based on the satellite signal distributed from a base station, satellite signal continuity information, which is information regarding the continuity of the satellite signal, is calculated based on the satellite signal and the satellite signal prediction information, and if continuity of the satellite signal is detected based on the satellite signal continuity information, it is determined that the mobile station is stationary.

The present invention makes it possible to realize a mobile positioning device and a mobile positioning method that have a simple configuration and that can determine the stationary state of a mobile station without relying on the detection accuracy of an inertial sensor.

1 is a diagram illustrating a hardware configuration of a stationary state determination system having a mobile object positioning device according to a first embodiment. FIG. 13 is a diagram showing a correction signal recorded in a correction signal DB. 11A and 11B are diagrams for explaining a pseudorange and a carrier phase calculated by a correction signal prediction unit as correction signal prediction information. 11 is a diagram showing parameters of a mathematical model calculated as correction signal prediction information by a correction signal prediction unit based on a correction signal DB. FIG. 2 is a diagram showing a correction signal prediction error, which is a difference between a correction signal received from the arithmetic control unit in FIG. 1 and a predicted value predicted from correction signal prediction information. 2 is a diagram showing a correction signal prediction error distribution calculated by the correction signal prediction result DB in FIG. 1 from the correction signal prediction error. 11 is a diagram showing a mathematical model relating to a pseudorange and a carrier phase calculated by a satellite signal prediction unit as satellite signal prediction information. FIG. 13 is a diagram showing parameters of a mathematical model calculated as satellite signal prediction information by a satellite signal prediction unit based on a corrected signal prediction result DB. FIG. 10 is a flowchart showing the process of a satellite signal continuity determination unit. 2 is a diagram showing the data configuration of position information and stationary state information output by the calculation control unit in FIG. 1 . 4 is a flowchart showing a process of the mobile positioning device. 4 is a flowchart showing a process of the mobile positioning device. 4 is a flowchart showing a process of the mobile positioning device. 10 is a flowchart showing a processing procedure performed by a satellite signal continuity determination unit in the second embodiment to detect the continuity of a satellite signal.

Below, an embodiment of a stationary state determination system for a mobile station and a determination method in the stationary state determination system according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions will be omitted.

Furthermore, the present invention is not limited to these drawings, and some components may not be used, and the components of each embodiment described below can be combined as appropriate.

Example 1
A stationary state determination system 1 having a mobile object positioning device 2 according to the present invention is a system used for determining the stationary state of mobile objects such as automobiles, trains, agricultural machines, and construction machines.

Figure 1 is a diagram showing the hardware configuration of a stationary state determination system 1 having a mobile object positioning device 2 according to the first embodiment.

In FIG. 1, the stationary state determination system 1 includes a mobile positioning device 2, a positioning satellite 3, a base station 4, and a distribution server 5.

[Positioning satellite 3]
The positioning satellites 3 are composed of multiple artificial satellites positioned in satellite orbits above the earth, and form a global navigation satellite system (GNSS) by transmitting satellite signals 10 toward the ground. In the GNSS, some of the satellite signals 10 from the multiple positioning satellites 3 are received, and the multiple received satellite signals 10 are used to enable the GNSS antenna 29 to obtain its own position on the earth. The satellite signals 10 include at least the position information and satellite clock error of the positioning satellites 3. The positioning satellites 3 transmit satellite signals 10 in multiple frequency bands, thereby achieving redundancy of the GNSS.

The positioning system 1 according to the present embodiment 1 is described as using satellite signals 10 in a single frequency band, but the present invention can be similarly applied to a positioning system using satellite signals 10 in multiple frequency bands.

[Base station 4]
A plurality of base stations 4 are installed at different points on the earth, and receive satellite signals 10 transmitted by each of the positioning satellites 3. The base stations 4 transmit the satellite signals 10 received from the plurality of positioning satellites 3 to a distribution server 5 (details of which will be described later). The positions of all base stations 4 on the earth are measured in advance with high accuracy, and the position information is stored in the distribution server 5.

[Distribution Server 5]
The distribution server 5 generates a correction signal 11 by receiving the satellite signal 10 from the base station 4. The distribution server 5 generates the correction signal 11 by the RRS method. The RRS method generates the correction signal 11 from the satellite signal 10 received by the base station 4 located near the position based on generated position information 30 (described later) acquired from the positioning device 2 (described later).

The distribution server 5 may also generate the correction signal 11 using the VRS method. The VRS method generates a virtual reference station at an arbitrary position, and calculates the satellite signal 10 that would be received at the virtual reference station from the satellite signal 10 received at a base station 4 installed near the virtual reference station. The distribution server 5 generates the base station 4 as a virtual reference station near the position based on the generated position information 30 acquired from the positioning device 2, calculates the correction signal 11, and transmits the correction signal 11 to the positioning device 2.

The stationary state determination system 1 according to this embodiment 1 is described as using the RRS method as the distribution server 5, but the present invention can also be applied to a stationary state determination system 1 that uses the VRS method as the distribution server 5.

The distribution server 5 can be a paid service provided by a company other than the manufacturer of the mobile positioning device 2, such as a communications carrier. The distribution server 5 and the positioning device 2 can communicate bidirectionally via a network using wireless communication lines or other known wireless communication lines.

The distribution server 5 may transmit a new correction signal 11 to the mobile positioning device 2 according to the generated location information 30 acquired from the mobile positioning device 2. In this case, the distribution server 5 selects the base station 4 generated closest to the generated location information 30 acquired from the mobile positioning device 2, generates a correction signal 11 from the satellite signal 10 received from that base station 4, and transmits the correction signal 11 to the mobile positioning device 2.

Each base station 4 is assigned a base station ID 102 (see FIG. 2), which is information for identifying the base station 4. The distribution server 5 generates a correction signal 11 including the base station ID 102. The distribution server 5 changes the base station ID 102 included in the correction signal 11 every time the distribution server 5 changes the base station 4 selected according to the generated position information 30 acquired from the mobile positioning device 2. Thus, the mobile positioning device 2 can detect the switching of the base station 4 based on whether the base station ID 102 (see FIG. 2) stated in the correction signal 11 received from the distribution server 5 has changed.

The distribution server 5 calculates the pseudo-distance 7 (see FIG. 2) and carrier phase 8 (see FIG. 2) for each positioning satellite 3 based on the satellite signal 10 received from the base station 4, and calculates a correction signal 11 including the pseudo-distance 7 and carrier phase 8. The pseudo-distance 7 is the distance from the positioning satellite 3 to the GNSS antenna 29, calculated by measuring the time it takes for the satellite signal 10 transmitted from the positioning satellite 3 to be received by the GNSS antenna 29. The pseudo-distance 7 includes receiver clock error, satellite clock error, ionospheric delay, tropospheric delay, and other noise.

The carrier phase 8 is the phase difference between the satellite signal 10 transmitted by the positioning satellite 3 at the same time and the satellite signal 10 received by the GNSS antenna 29. The carrier phase 8 includes integer bias, receiver clock error, satellite clock error, ionospheric delay, tropospheric delay, and other noise.

The carrier phase 8 may be described as a distance component by multiplying it by the wavelength of the satellite signal 10 transmitted by the positioning satellite 3. In this case, the processing of the mobile positioning device 2 is performed by multiplying the carrier phase 8 by the inverse of the wavelength of the satellite signal 10. The correction signal 11 includes at least the pseudo-distance 7 of each positioning satellite 3 at the base station 4, the carrier phase 8, the position of the base station 4 on the Earth, and the base station ID 102.

[Mobile positioning device 2]
The mobile positioning device 2 calculates stationary state information 15 indicating the stationary state of the GNSS antenna 29 based on the satellite signal 10 received using the GNSS antenna 29 and the correction signal 11 acquired from the distribution server 5. In addition, the mobile positioning device 2 calculates position information 12 indicating the position of the GNSS antenna 29 based on the satellite signal 10 received using the GNSS antenna 29 and the correction signal 11 acquired from the distribution server 5.

As shown in FIG. 1, the mobile positioning device 2 includes a positioning calculation unit 20, a communication unit 21, a correction signal DB (correction signal database) 22, a correction signal prediction unit 23, and a correction signal prediction result DB (correction signal prediction result database) 24.

The mobile positioning device 2 further includes a satellite signal prediction unit 26, a satellite signal prediction result DB (satellite signal prediction result database) 25, a satellite signal continuity determination unit 27, a calculation control unit 28, and a GNSS antenna 29.

The positioning calculation unit 20, the communication unit 21, the correction signal DB 22 (correction signal recording unit), the correction signal prediction unit 23, the correction signal prediction result DB 24, the satellite signal prediction unit 26, the satellite signal prediction result DB 25, and the satellite signal continuity determination unit 27 execute processing determined in response to an operational command from the calculation control unit 28.

The calculation control unit 28 outputs the position information 12 and the stationary state information 15 according to the operating cycle of the positioning calculation unit 20. Each element of the mobile positioning device 2 may be configured so that its function is realized by hardware, or by software by executing a computer program. Furthermore, each element of the mobile positioning device 2 does not necessarily have to be configured within a single piece of hardware, but may be configured as separate independent devices, such as external devices or external servers. In that case, each element of the mobile positioning device 2 should be configured to be able to communicate with each other.

[GNSS antenna 29]
The GNSS antenna 29 receives satellite signals 10 from a plurality of positioning satellites 3 positioned above the Earth, and transmits the received satellite signals 10 to the calculation control unit 28. Here, the satellite signals 10 are analog signals, and the GNSS antenna 29 is configured to A/D convert the received satellite signals 10 and transmit the satellite signals 10 as digital signals to the positioning calculation unit 29.

The GNSS antenna 29 is installed at a location on the object to be positioned where it is desired to obtain the position. For example, if the mobile object positioning device 2 is used in a vehicle, the GNSS antenna 29 may be installed on the body of the vehicle, which is the target mobile object.

[Positioning calculation unit 20]
The positioning calculation unit 20 calculates the position of the GNSS antenna 29 on the earth based on the satellite signal 10 and the correction signal 11 from the positioning satellite 3 received from the calculation control unit 28, and calculates one or more of approximate position data 13 and precise position data 14. The positioning calculation unit 20 outputs one of the calculated approximate position data 13 and precise position data 14 to the calculation control unit 28 as position information 12.

The approximate position data 13 is the approximate position of the GNSS antenna 29 calculated by the positioning calculation unit 20 using single point positioning. The precise position data 14 is the precise position of the GNSS antenna 29 calculated by the positioning calculation unit 20 using interferometric positioning. The precise position data 14 is a highly accurate positioning result that is closer to the actual position of the GNSS antenna 29 than the approximate position data 13.

The positioning calculation unit 20 calculates the pseudo distance 7 and carrier phase 8 for each positioning satellite 3 based on the satellite signal 10 received by the GNSS antenna 29, thereby calculating one or more of the approximate position data 13 and the precise position data 14.

In standalone positioning, the positioning calculation unit 20 calculates approximate position data 13 based on multiple satellite signals 10 received by the GNSS antenna 29. In standalone positioning, the approximate position data 13 is calculated using the principle of triangulation from pseudo distances 7 between at least four or more positioning satellites 3 and the GNSS antenna 29. The pseudo distances 7 include errors due to the orbit of each positioning satellite 3, the accuracy of the clocks used in the mobile positioning device 2 and the positioning satellite 3, and delays in the carrier wave that occur when passing through the ionosphere and troposphere.

In interferometric positioning, the positioning calculation unit 20 calculates precise position data 14 based on both the satellite signal 10 received by the GNSS antenna 29 and the correction signal 11 received from the calculation control unit 28. In interferometric positioning, the precise position data 14 is calculated from the pseudo distances 7 and carrier phases 8 between at least five or more positioning satellites 3 and the GNSS antenna 29 contained in the satellite signal 10 received by the GNSS antenna 29, and the pseudo distances 7 and carrier phases 8 between at least five or more positioning satellites 3 and the base station 4 contained in the correction signal 11.

In addition, in interferometric positioning, a carrier phase difference is calculated, which is the difference between the carrier phase 8 between the positioning satellite 3 and the GNSS antenna 29 and the carrier phase 8 between the positioning satellite 3 and the base station 4. In interferometric positioning, when the GNSS antenna 29 receives the satellite signal 10, the decimal part of the wave number indicating which part of the continuous wave it is in the carrier phase 8 of the satellite signal 10 is known, but the integer part of the wave number excluding the decimal part of the wave number is unknown. In interferometric positioning, when this integer part of the wave number is determined, the baseline length between the base station 4 and the GNSS antenna 29 can be accurately determined.

In interferometric positioning, the position of the base station 4 on Earth is recorded in the correction signal 11, so the position of the GNSS antenna 29 can be predicted from the baseline length between the position of the base station 4 and the GNSS antenna 29.

The positioning calculation unit 20 therefore calculates precise position data 14 by correcting the approximate position data 13, which is the result of independent positioning, using the position of the GNSS antenna 29 predicted from the baseline length between the position of the base station 4 and the GNSS antenna 29. At this time, the positioning calculation unit 20 assumes that the wave number integer part included in the carrier phase difference at the past time and the wave number integer part at the current time are continuous, and calculates the precise position data 14 by using a Kalman filter or the like.

When the positioning calculation unit 20 receives a calculation initialization command from the calculation control unit 28, it discards the assumption that the wave number integer part up to that point was continuous, and starts calculating the wave number integer part and baseline length again. Immediately after receiving the calculation initialization command, the positioning calculation unit 20 can only estimate the wave number decimal part of the continuous wave at the carrier phase 8 of the satellite signal 10, so the positioning accuracy temporarily decreases until the wave number integer part of the continuous wave is determined. If the positioning calculation unit 20 cannot determine the wave number decimal part and wave number integer part of the carrier phase difference, it determines that the interferometric positioning calculation has failed.

If the positioning calculation unit 20 is able to calculate the precise position data 14, it outputs the precise position data 14 as the position information 12, and only if the positioning calculation unit 20 is unable to calculate the precise position data 14, it outputs the approximate position data 13 as the position information 12. The positioning calculation unit 20 outputs the position information 12 to the calculation control unit 28.

[Communication unit 21]
The communication unit 21 transmits the generated position information region received from the calculation control unit 28 to the distribution server 5. The distribution server 5 generates a correction signal 11 according to the generated position information 30 received from the communication unit 21, and outputs it to the communication unit 21. The correction signal 11 received by the communication unit 21 from the distribution server 5 includes at least a satellite identification number 100 (see FIG. 2 ), which is an identification number of the positioning satellite 3, a correction signal generation time 101 (see FIG. 2 ), which is the time when the correction signal 11 was generated, a base station ID 102, a pseudo distance 7, and a carrier phase 8. The communication unit 21 outputs the correction signal 11 received from the distribution server 5 to the calculation control unit 28. For example, when there is a radio wave interference or a failure occurs in either the communication unit 21 or the distribution server 5, the communication unit 21 may fail to receive the correction signal 11.

[Correction signal DB22]
The correction signal DB 22 records the correction signal 11 in accordance with an instruction from the calculation control unit 28. The correction signal DB 22 records at least the satellite identification number 100, the correction signal generation time 101, the base station ID 102, the pseudo distance 7, and the carrier phase 8 as the correction signal 11 previously received from the calculation control unit 28. The correction signal DB 22 acquires the correction signal 11 received by the calculation control unit 28 from the distribution server 5 via the communication unit 21 from the calculation control unit 28, and stores the correction signal 11.

Figure 2 shows a data table showing details of the correction signal 11 recorded by the correction signal DB 22.

The correction signal DB 22 stores the correction signals 11 in chronological order of the correction signal generation time 101, and at the same time, stores the correction signals 11 at least in order of the satellite identification number 100. If a correction signal 11 has already been recorded for the same time and from the same positioning satellite 3 as the correction signal 11 received from the calculation control unit 28, the correction signal DB 22 updates the pseudo distance 7, carrier phase 8, and base station ID 102 of the recorded correction signal 11.

The correction signal DB 22 determines that the data group with the most recent recorded correction signal generation time 101 is the latest correction signal 11. FIG. 2 shows an example in which correction signals 11 with correction signal generation times 101 from 07:00:00 to 07:30:00 are stored, and the data group with a correction signal generation time 101 of "07:30:00" corresponds to the latest correction signal 11.

The correction signal DB 22 is configured in a state where the correction signal 11 can always be referenced by the correction signal prediction unit 23 and the calculation control unit 28. If the correction signal DB 22 cannot secure sufficient storage space, for example, it may record the correction signal 11 only for a predetermined fixed period of time, and when the recording time exceeds the fixed period, execute a process of deleting the oldest record. Furthermore, when the correction signal DB 22 receives an initialization command from the calculation control unit 28, it deletes all records of the recorded correction signal 11.

[Correction signal prediction unit 23]
Based on the correction signal 11 recorded in the correction signal DB 22 and the correction signal 11 from the calculation control unit 28, the correction signal prediction unit 23 calculates correction signal prediction information 18 from the correction signal 11 recorded in the correction signal DB 22 and the correction signal 11 received from the calculation control unit 28. In other words, the correction signal prediction unit 23 calculates correction signal prediction information 18 including a prediction model of the correction signal 11 to be distributed by the base station 4 at the current time or in the future, from the correction signal 11 received in the past.

The correction signal prediction unit 23 constructs a mathematical model for predicting the pseudo distance 7 and carrier phase 8 described in the correction signal 11 received from the calculation control unit 28 based on the correction signal 11 (past correction signal 11) recorded in the correction signal DB 22, and calculates it as correction signal prediction information 18. Hereinafter, in this specification, the time described in the correction signal 11 received by the correction signal prediction unit 23 from the calculation control unit 28 is referred to as "t".

Figure 3 is a diagram showing a mathematical model for the pseudo-distance 7 and carrier phase 8 calculated by the correction signal prediction unit 23 as the correction signal prediction information 18. Figure 3 is a graph of the mathematical model. As shown in Figure 3, the correction signal prediction information 18 is expressed by a mathematical model calculated using the values of the pseudo-distance 7 and carrier phase 8 at a preset number of times, for example, the past five times recorded in the correction signal DB 22.

If the five past times recorded in the correction signal DB22 are _{t1, t2, t3, t4, and t5, respectively, and the pseudoranges 7 or carrier phases 8 corresponding to these times are y1 , y2 , y3 , y4 , and y5} , respectively, these can be expressed by the following equations (1) and (2), and the predicted value of the pseudorange 7 or carrier phase 8 at time t can be obtained by the following equation (3).

The "T" in the above formula (2) will be explained later.

The correction signal prediction unit 23 constructs a mathematical model for all positioning satellites 3 described in the correction signal 11 received from the calculation control unit 28 at time t based on the correction signal DB 22 and the calculation control unit 28, and calculates the correction signal prediction information 18.

Figure 4 shows the parameters of the mathematical model that the correction signal prediction unit 23 calculates as the correction signal prediction information 18 based on the correction signal DB 22.

The correction signal prediction unit 23 calculates the parameters of a mathematical model that predicts the pseudo-range 7 and carrier phase 8 of each positioning satellite 3 at time t as correction signal prediction information 18. For example, when the pseudo-range 7 and carrier phase 8 of a specific positioning satellite 3 are recorded in the correction signal DB 22 at five or more times in the past, the correction signal prediction unit 23 calculates the correction signal prediction information 18 corresponding to the positioning satellite 3.

If the correction signal prediction unit 23 has not recorded the pseudorange 7 and carrier phase 8 of a specific positioning satellite 3 for the past five or more times, it does not calculate correction signal prediction information 18 for the positioning satellite 3.

As shown in FIG. 5, the correction signal prediction unit 23 calculates the difference between the correction signal 11 received from the calculation control unit 28 and the predicted value predicted from the correction signal prediction information 18 as the correction signal prediction error 36. The correction signal prediction unit 23 may calculate the correction signal prediction information 18 and the correction signal prediction error 36 only when the correction signal 11 is received from the calculation control unit 28, or may set a control period such as 5 seconds or 10 seconds and calculate the correction signal prediction information 18 and the correction signal prediction error 36 for the correction signal 11 received from the calculation control unit 28 most recently in the control period. The correction signal prediction unit 23 outputs the correction signal prediction information 18 and the correction signal prediction error 36 to the correction signal prediction result DB 24.

[Correction signal prediction result DB24]
The correction signal prediction result DB 24 records the correction signal prediction information 18 and the correction signal prediction error distribution 37 (see FIG. 6 ) of the positioning satellite 3 based on the output of the correction signal prediction unit 23. The correction signal prediction result DB 24 records the correction signal prediction information 18 in the format shown in FIG. 4. The correction signal prediction result DB 24 receives and records the correction signal prediction error 36 from the correction signal prediction unit 22, and calculates the correction signal prediction error distribution 37, which is the probability distribution of the correction signal prediction error 36.

As a result, by setting the vertical axis to indicate the occurrence probability and the horizontal axis to indicate the correction signal prediction error 36, a graph like that shown in Figure 6 can be generated, which represents the correction signal prediction error distribution 37.

The correction signal prediction result DB 24 calculates and records the correction signal prediction error distribution 37 for all positioning satellites 3 for which the correction signal prediction information 18 was calculated. The correction signal prediction result DB 24 is configured to allow the satellite signal prediction unit 26 and the satellite signal continuity determination unit 27 to refer to the correction signal prediction information 18 and the correction signal prediction error distribution 37.

For example, if there is a positioning satellite 3 whose correction signal prediction information 18 has not been updated for a predetermined period of time or longer, the correction signal prediction result DB 24 may execute a process of deleting the correction signal prediction information 18 and correction signal prediction error distribution 37 associated with the positioning satellite 3 recorded in the correction signal prediction result DB 24.

In addition, when the correction signal prediction result DB 24 receives an initialization command from the calculation control unit 28, it deletes the correction signal prediction information 18 and correction signal prediction error distribution 37 of all recorded positioning satellites 3.

[Satellite signal prediction unit 26]
In summary, the satellite signal prediction unit 26 calculates satellite signal prediction information 19 including a prediction model of the satellite signal 10 to be distributed at the current time or in the future based on the satellite signal 10 received by the mobile station 29 and a correction signal 11 based on the satellite signal 10 distributed from the base station 4.

The satellite signal prediction unit 26 operates only when it receives a satellite signal 10 from the calculation control unit 28. Based on the correction signal prediction result DB 24 and the calculation control unit 28, the satellite signal prediction unit 26 calculates satellite signal prediction information 19 from the correction signal prediction information 18 recorded in the correction signal prediction result DB 24 and the satellite signal 10 received from the calculation control unit 28.

The satellite signal prediction unit 26 constructs a mathematical model (a prediction model of the satellite signal 10 to be distributed at the current time or in the future) for predicting the satellite signal 10 to be next received by the GNSS antenna 29, assuming that the GNSS antenna 29 is stationary, from the predicted value of the correction signal 11 calculated using the correction signal prediction information 18 recorded in the correction signal prediction result DB 24 and the satellite signal 10, and calculates it as satellite signal prediction information 19.

Hereinafter, in this specification, the time indicated in the satellite signal 10 received by the satellite signal prediction unit 26 from the calculation control unit 28 will be referred to as "T."

Figure 7 shows a mathematical model for the pseudorange 7 and carrier phase 8 that the satellite signal prediction unit 26 calculates as satellite signal prediction information 19. Figure 7 shows a graph of the mathematical model.

As shown in FIG. 7, the satellite signal prediction information 19 calculates the difference d between the pseudorange 7 or carrier phase 8 described in the predicted value of the correction signal 11 calculated from the satellite signal 10 at time T and the correction signal prediction information 18 using the following equation (4).

Then, the satellite signal prediction unit 26 corrects the mathematical model of the corrected signal prediction information 18 using the difference d calculated by the above formula (4), and calculates the satellite signal prediction information 19 using the following formula (5) that can calculate the pseudorange 7 and carrier phase 8 of the satellite signal 10 received by the GNSS antenna 29, assuming that the GNSS antenna 29 is stationary at an arbitrary time "T1".

In other words, the satellite signal prediction unit 26 calculates satellite signal prediction information 19 based on the satellite signal 10 and the correction signal prediction information 18 by correcting the correction signal prediction information 18 with the satellite signal 10.

The satellite signal prediction unit 26 outputs the calculated satellite signal prediction information 19 to the satellite signal prediction result DB 25.

[Satellite signal prediction result DB25]
The satellite signal prediction result DB 25 records satellite signal prediction information 19 of the positioning satellites 3 based on the outputs of the satellite signal prediction unit 26 and the calculation control unit 28. The satellite signal prediction result DB 25 records the satellite signal prediction information 19 in the format shown in Fig. 8. The satellite signal prediction result DB 25 is configured to allow the satellite signal continuity determination unit 27 to refer to the satellite signal prediction information 19.

For example, if there is a positioning satellite 3 whose satellite signal prediction information 19 has not been updated for a predetermined period of time or more, the satellite signal prediction result DB 25 may execute a process of deleting the satellite signal prediction information 19 linked to the positioning satellite 3 recorded in the satellite signal prediction result DB 25. In addition, if the satellite signal prediction result DB 25 receives an initialization command from the calculation control unit 28, it deletes the satellite signal prediction information 19 of all recorded positioning satellites 3.

[Satellite signal continuity determination unit 27]
The satellite signal continuity determination unit 27 operates only when it receives a satellite signal 10 from the calculation control unit 28. The satellite signal continuity determination unit 27 detects the continuity of the pseudorange 7 and carrier phase 8 described in the satellite signal 10 received by the GNSS antenna 29, based on information from the correction signal prediction result DB 24, the satellite signal prediction result DB 25, and the calculation control unit 28, using the correction signal prediction error distribution 37 recorded in the correction signal prediction result DB 24, the satellite signal prediction information 19 recorded in the satellite signal prediction result DB 25, and the satellite signal 10 received from the calculation control unit 28.

The satellite signal continuity determination unit 27 notifies the calculation control unit 28 of the continuity of the pseudo distance 7 and carrier phase 8 described in the satellite signal 10 received from the calculation control unit 28 as satellite signal continuity information 16. The calculation control unit 28 can estimate the operating state of the GNSS antenna 29 according to the continuity of the pseudo distance 7 and carrier phase 8 described in the satellite signal 10 received from the satellite signal continuity determination unit 27. In the following embodiment, the satellite signal continuity determination unit 27 detects only the continuity of the carrier phase 8, but the present invention can also be similarly applied when the pseudo distance 7 is used.

Figure 9 is a flowchart showing the processing of the satellite signal continuity determination unit 27. The flowchart shown in Figure 9 shows the processing performed by the satellite signal continuity determination unit 27 after the satellite signal continuity determination unit 27 receives the satellite signal 10 from the calculation control unit 28.

In step S301, it is confirmed whether satellite signal prediction information 19 is recorded in satellite signal prediction result DB 25. If satellite signal prediction information 19 is recorded in satellite signal prediction result DB 25, the process proceeds to step S302, and if not, the process proceeds to step S310.

In step S302, S_SUM, which is the total number of positioning satellites 3 listed in the satellite signal 10 received from the calculation control unit 28, is calculated.

In step S303, it is confirmed whether S_SUM is 5 or more and whether interferometric positioning is possible. If there are 5 or more, the first positioning satellite 3 listed in the satellite signal 10 is selected as S (step S303a), N is set to 0 (step S303b), and the process proceeds to step S304.

If S_SUM is less than 5 in step S303, proceed to step S310.

In step S304, the above-mentioned mathematical model of the satellite signal prediction information 19 is used to predict the carrier phase 8 of the satellite signal 10 related to the positioning satellite S at the time t when the GNSS antenna 29 receives the satellite signal 10, which is contained in the satellite signal 10 received from the calculation control unit 28.

In step S305, a carrier phase prediction error ε1 is calculated, which is the difference between the predicted value of carrier phase 8 calculated in step 304 and the actual measured value of carrier phase 8 contained in the satellite signal 10 received from the calculation control unit 28.

In step S306, a carrier phase prediction error threshold ε1_MAX is calculated, which is a threshold for determining whether the carrier phase 8 for the positioning satellite S described in the satellite signal 10 in step S304 has been accurately predicted.

The carrier phase prediction error threshold ε1_MAX may be, for example, a threshold value of the 1σ, 2σ, or 3σ interval of the correction signal prediction error distribution 37 recorded in the correction signal prediction result DB24, and when the carrier phase prediction error ε1 calculated in step S305 exceeds the threshold value, it may be determined that the carrier phase 8 for the positioning satellite S has not been accurately predicted.

In step S307, it is determined whether the carrier phase prediction error ε1 is equal to or greater than the carrier phase prediction error threshold ε1_MAX. In step S307, if the carrier phase prediction error ε1 is equal to or greater than ε1_MAX, the number of satellites N for which the continuity of the carrier phase 8 has been lost is counted (step S307a), and the process proceeds to step S308. In step S307, if the carrier phase prediction error ε1 is less than the carrier phase prediction error threshold ε1_MAX, no specific processing is performed and the process proceeds to step S308.

In step S308, it is determined whether or not all of the positioning satellites 3 described in the satellite signal 10 received from the calculation control unit 28 have been selected as positioning satellites S. If all of the positioning satellites 3 have been selected, the process proceeds to step S309.

If all positioning satellites 3 have not been selected in step S308, the next positioning satellite 3 is selected as S (step S308a) and the process returns to step S304.

In step S309, it is determined whether the number N of satellites for which continuity of carrier phase 8 has been lost is equal to or greater than the positioning satellite number threshold N_MAX. If the number N of satellites for which continuity has been lost is less than the positioning satellite number threshold N_MAX, proceed to step S312. If the number N of satellites for which continuity has been lost is equal to or greater than the positioning satellite number threshold N_MAX, proceed to step S311.

The method for determining the positioning satellite number threshold N_MAX may be, for example, set based on whether the continuity of the carrier phase 8 has been lost for α% or more of the positioning satellites 3 described in the satellite signal 10 received from the calculation control unit 28. In this case, the calculation formula for the positioning satellite number threshold N_MAX is given by the following equation (6) with S_SUM as a variable. Note that α in the following equation (6) is a predetermined percentage.

In step S310 shown above, the satellite signal continuity determination unit 27 does not output the satellite signal continuity information 16 of the satellite signal 10 received from the calculation control unit 28 to the calculation control unit 28.

In step S311, the satellite signal continuity determination unit 27 outputs satellite signal continuity information 16 to the calculation control unit 28, indicating that there is no continuity in the satellite signal 10 received from the calculation control unit 28.

In step S312, the satellite signal continuity determination unit 27 outputs satellite signal continuity information 16 to the calculation control unit 28, indicating that there is continuity in the satellite signal 10 received from the calculation control unit 28.

[Calculation control unit 28]
The calculation control unit 28 obtains location information 12 from the positioning calculation unit 20 and obtains satellite signal continuity information 16 from the satellite signal continuity determination unit 27 by issuing operational commands to the positioning calculation unit 20, the communication unit 21, the correction signal prediction unit 23, the satellite signal prediction unit 26 and the satellite signal continuity determination unit 27.

The calculation control unit 28 calculates stationary state information 15, which is the stationary state of the GNSS antenna 29, according to the satellite signal continuity information 16 acquired from the satellite signal continuity determination unit 27. The calculation control unit 28 then transmits the acquired position information 12 and the calculated stationary state information 15 to an external terminal (not shown) (when it is determined that the mobile station 29 is stationary, it calculates stationary state information 15 indicating the stationary state and transmits it to the external terminal). The external terminal is not limited to this embodiment, and for example, when the present invention is used in a mobile body position/attitude estimation system, a vehicle control module or an inertial sensor calibration module that requires the mobile body position information 12 and stationary state information 15 corresponds to the external terminal.

The calculation control unit 28 refers to and edits the data recorded in the correction signal DB 22, the correction signal prediction result DB 24, and the satellite signal prediction result DB 25. The order in which the calculation control unit 28 issues operation commands to the positioning calculation unit 20, the communication unit 21, the correction signal prediction unit 23, the satellite signal prediction unit 26, and the satellite signal continuity determination unit 27, and the method of determination thereof, will be described later.

The calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 to the positioning calculation unit 20, thereby instructing the positioning calculation unit 20 to calculate the position information 12. When the calculation control unit 28 has acquired a correction signal 11 from the distribution server 5 via the communication unit 21, it transmits the satellite signal 10 and the correction signal 11 to the positioning calculation unit 20, thereby instructing the positioning calculation unit 20 to calculate the position information 12.

The calculation control unit 28 receives the correction signal 11 corresponding to the base station 4 from the distribution server 5 by transmitting the generated position information 30 to the distribution server 5 via the communication unit 21. The generated position information 30 is position information for the distribution server 5 to select the base station 4 that generates the correction signal 11, and is recorded in the calculation control unit 28. The distribution server 5 selects the base station 4 that generates the correction signal 11 according to the position information 12 received from the calculation control unit 28.

When the base station ID 102 of the correction signal 11 received from the communication unit 21 has changed, the calculation control unit 28 determines that the distribution server 5 has changed the base station 4 that generates the correction signal 11. When the base station 4 that generates the correction signal 11 has changed, the calculation control unit 28 initializes the calculation of the positioning calculation unit 20.

Then, the calculation control unit 28 transmits the correction signal 11 received from the communication unit 21 to the correction signal prediction unit 23, thereby instructing the correction signal prediction unit 23 to calculate the correction signal prediction information 18. The calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 to the satellite signal prediction unit 26, thereby instructing the satellite signal prediction unit 26 to calculate the satellite signal prediction information 19.

The calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 to the satellite signal continuity determination unit 27, thereby instructing the satellite signal continuity determination unit 27 to calculate the satellite signal continuity information 16.

The calculation control unit 28 outputs the position information 12 and stationary state information 15 in the format shown in FIG. 10. The calculation control unit 28 links the output time 103, which is the time when the satellite signal 10 used by the positioning calculation unit 20 to calculate the position information 12 was received by the GNSS antenna 29, with the position information 12 and stationary state information 15 calculated using the satellite signal 10, and transmits them to an external terminal (not shown).

For ease of explanation, FIG. 10 shows the output time 103, position information 12, and stationary state information 15 in table format, but the calculation control unit 28 does not transmit the position information 12 and stationary state information 15 at multiple output times all at once. Rather, it links the position information 12 received from the positioning calculation unit 20 and the stationary state information 15 calculated by the calculation control unit 28 to the output time and transmits them each time to an external terminal (not shown).

The calculation control unit 28 receives the satellite signal continuity information 16 from the satellite signal continuity determination unit 27 and calculates the stationary state information 15. When the calculation control unit 28 receives the satellite signal continuity information 16 indicating that there is continuity, it outputs the stationary state information 15 to the external terminal as stationary, as shown in FIG. 10.

When the calculation control unit 28 receives the satellite signal continuity information 16 indicating no continuity, it outputs the stationary state information 15 as an operation to the external terminal, as shown in FIG. 10.

If the calculation control unit 28 does not receive satellite signal continuity information 16, it outputs the stationary state information 15 as NULL to the external terminal, as shown in FIG. 10.

[Overall mobile positioning device 2]
Hereinafter, the order in which the arithmetic and control unit 28 issues operational commands and the method of determining the order will be described with reference to FIGS. 11, 12 and 13, thereby explaining the processing of the mobile positioning device 2. FIG.

The process shown below is executed each time the GNSS antenna 29 receives a satellite signal 10 from a positioning satellite 3.

Fig. 11 is a flowchart showing steps S201 to S207 of the processing of the mobile positioning device 2. Fig. 12 is a flowchart showing steps S208 to S217 of the processing of the mobile positioning device 2. Fig. 13 is a flowchart showing steps S218 to S232 of the processing of the mobile positioning device 2.

In FIG. 11, in step S201, the GNSS antenna 29 transmits the satellite signal 10 received from the positioning satellite 3 to the calculation control unit 28.

In step S202, the calculation control unit 28 transmits the satellite signal 10 acquired from the GNSS antenna 29 to the satellite signal continuity determination unit 27 and commands the satellite signal continuity determination unit 27 to perform calculations. The satellite signal continuity determination unit 27 executes the processes from step S301 to step S312 shown in FIG. 9.

In step S203, the calculation control unit 28 checks whether it has received satellite signal continuity information 16 from the satellite signal continuity determination unit 27. If it has received satellite signal continuity information 16, the process proceeds to step S204. If it has not received satellite signal continuity information 16 in step S203, the calculation control unit 28 proceeds to step S207.

In step S204, the calculation control unit 28 checks whether the satellite signal continuity information 16 received from the satellite signal continuity determination unit 27 states "continuity exists." If the satellite signal continuity information 16 states "continuity exists," the process proceeds to step S205. If the satellite signal continuity information 16 does not state "continuity exists," the process proceeds to step S206.

In step S205, the calculation control unit 28 calculates the stationary state information 15 as "stationary."

In step S206, the calculation control unit 28 calculates the stationary state information 15 as "motion."

In step S207, the calculation control unit 28 calculates the stationary state information 15 as "NULL."

Next, in step S208 of FIG. 12, it is confirmed whether the calculation control unit 28 has recorded the generation position information 30. If the calculation control unit 28 has recorded the generation position information 30, the process proceeds to step S209. If the calculation control unit 28 has not recorded the generation position information 30 in step S208, the process proceeds to step S227 (shown in FIG. 13).

In step S209, the calculation control unit 28 transmits the generated position information 30 to the communication unit 21.

In step S210, the communication unit 21 receives the correction signal 11 from the distribution server 5 by transmitting the generated position information 30 received from the calculation control unit 28 to the distribution server 5. The communication unit 21 transmits the correction signal 11 received from the distribution server 5 to the calculation control unit 28.

In step S211, the calculation control unit 28 checks whether or not the correction signal 11 has been received from the distribution server 5 via the communication unit 21. If the calculation control unit 28 has received the correction signal 11, the process proceeds to step S212. If the calculation control unit 28 has not received the correction signal 11, the process proceeds to step S223 (shown in FIG. 13).

In step S212, the calculation control unit 28 checks whether or not the correction signal 11 is recorded in the correction signal DB 22. If the correction signal 11 is recorded in the correction signal DB 22, the process proceeds to step S213. If the correction signal 11 is not recorded in the correction signal DB 22, the process proceeds to step S218 (shown in FIG. 13).

In step S213, the calculation control unit 28 checks whether the base station ID 102 of the correction signal 11 received from the communication unit 21 in step S210 is the same as the base station ID 102 of the correction signal 11 recorded in the correction signal DB 22. If the base station ID 102 of the received correction signal 11 is the same as the base station ID 102 of the recorded correction signal 11, the process proceeds to step S218 (shown in FIG. 13), and if they are not the same, the process proceeds to step S214.

In step S214, the calculation control unit 28 initializes the correction signal DB22 by deleting the correction signal 11 recorded in the correction signal DB22.

In step S215, the calculation control unit 28 initializes the correction signal prediction result DB 24 by deleting the correction signal prediction information 18 recorded in the correction signal prediction result DB 24.

In step S216, the calculation control unit 28 initializes the satellite signal prediction result DB 25 by deleting the satellite signal prediction information 19 recorded in the satellite signal prediction result DB 25.

In step S217, the calculation control unit 28 sends an initialization command to the positioning calculation unit 20, thereby initializing the positioning calculation of the positioning calculation unit 20.

In step S218 (shown in FIG. 13), the calculation control unit 28 transmits the correction signal 11 received from the communication unit 21 in step S210 to the correction signal prediction unit 23, and commands the correction signal prediction unit 23 to process. After that, the correction signal prediction unit 23 transmits the correction signal prediction information 18 and the correction signal prediction error 36 to the correction signal prediction result DB 24, and the correction signal prediction result DB 24 records the correction signal prediction information 18 and the correction signal prediction error distribution 37.

In step S219, the calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 in step S201 to the satellite signal prediction unit 26, and commands the satellite signal prediction unit 26 to process it. After that, the satellite signal prediction unit 26 transmits the satellite signal prediction information 19 to the satellite signal prediction result DB 25, and the satellite signal prediction result DB 25 records the satellite signal prediction information 19.

In step S220, the calculation control unit 28 records the correction signal 11 received from the communication unit 21 in step S210 in the correction signal DB 22.

In step S221, the calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 in step S201 to the positioning calculation unit 20.

In step S222, the calculation control unit 28 transmits the correction signal 11 received from the communication unit 21 in step S210 to the positioning calculation unit 20.

In step S223, the calculation control unit 28 transmits the satellite signal 10 received from the GNSS antenna 29 in step S201 to the positioning calculation unit 20.

In step S224, the calculation control unit 28 checks whether or not the correction signal 11 is recorded in the correction signal DB 22. If the correction signal 11 is recorded in the correction signal DB 22, the process proceeds to step S225. If the correction signal 11 is not recorded in the correction signal DB 22, the process proceeds to step S227.

In step S225, the calculation control unit 28 transmits the correction signal 11 recorded in the correction signal DB 22 to the positioning calculation unit 20.

In step S226, the calculation control unit 28 commands the positioning calculation unit 20 to perform interferometric positioning.

In step S227, the calculation control unit 28 commands the positioning calculation unit 20 to perform independent positioning.

In step S228, the calculation control unit 28 judges whether the positioning calculation unit 20 has succeeded in the interferometric positioning. Here, the calculation control unit 28 judges that the interferometric positioning has been successful when the positioning calculation unit 20 has determined either the wave number decimal part or the wave number integer part of the carrier phase difference. If the interferometric positioning has been successful, the process proceeds to step S229. If the interferometric positioning has failed, the process proceeds to step S230.

In step S229, the positioning calculation unit 20 calculates precise position data 14 by correcting the independent positioning result with the interferometric positioning result, and outputs the precise position data 14 to the calculation control unit 28 as position information 12.

In step S230, the positioning calculation unit 20 calculates the approximate position data 13, which is the result of independent positioning, and outputs it to the calculation control unit 28 as position information 12.

In step S231, the calculation control unit 28 outputs the position information 12 and stationary state information 15 to the external terminal.

In step S232, the calculation control unit 28 records the location information 12 acquired from the positioning calculation unit 20 as generated location information 30, and then ends the process.

In the mobile positioning device 2 of this embodiment 1, the satellite signal 10 received by the GNSS antenna 29 from the positioning satellite 3 and the correction signal 11 received by the communication unit 21 from the distribution server 5 are used to predict the satellite signal 10 received by the GNSS antenna 29 from the positioning satellite 3, and the continuity of the satellite signal 10 received by the GNSS antenna 29 is detected from the deviation between the predicted value and the actual measured value.

Then, if the mobile positioning device 2 detects continuity of the received satellite signal 10, it determines that the GNSS antenna 29 is stationary.

With this configuration, it becomes possible to determine the stationary state of a moving object using only GNSS without installing an attitude measurement device, etc., and the structure can be simplified.

According to the present embodiment 1, in the stationary state determination system, it is possible to determine the continuity of the satellite signal 10 obtained from the positioning satellite 3 and the correction signal obtained from the base station 4. If the acquired satellite signal 10 is continuous, the stationary state determination system can determine that the vehicle is in a stationary state, which enables a simplified configuration and stationary state determination that does not depend on an inertial sensor.

In other words, according to the first embodiment of the present invention, it is possible to realize a mobile positioning device and a mobile positioning method that have a simple configuration and that can determine the stationary state of a mobile station without relying on the detection accuracy of an inertial sensor.

Example 2
Next, a second embodiment of the present invention will be described.

The mobile positioning device 2 of this embodiment 2 has the same configuration as that of the first embodiment, but differs from that of the first embodiment in the processing of the satellite signal prediction unit 26, the satellite signal prediction result DB 25, the satellite signal continuity determination unit 27, and the calculation control unit 28. Therefore, the overall configuration of the second embodiment is the same as that of FIG. 1, and is therefore not shown in the figure.

The differences between Example 1 and Example 2 are explained below.

The difference between Example 2 and Example 1 is that when the calculation control unit 28 calculates the stationary state information 15 as "stationary", the calculation control unit 28 instructs the satellite signal prediction result DB 25 to calculate the satellite signal prediction error distribution 39, and the satellite signal continuity determination unit 27 determines the continuity of the satellite signal 10 based on the satellite signal prediction error distribution 39 calculated by the satellite signal prediction result DB 25, and calculates the satellite signal continuity information 16.

[Satellite signal prediction result DB25]
Based on the satellite signal prediction unit 26 and the calculation control unit 28, the satellite signal prediction result DB 25 calculates the difference between the satellite signal 10 received from the calculation control unit 28 and the predicted value predicted from the satellite signal prediction information 19 as the satellite signal prediction error 38.

Then, the satellite signal prediction result DB25 receives and records the calculated satellite signal prediction error 38, thereby calculating a satellite signal prediction error distribution 39, which is a probability distribution of the satellite signal prediction error 38. The satellite signal prediction result DB25 calculates the satellite signal prediction error distribution 39 only when instructed by the calculation control unit 28 to calculate the satellite signal prediction error distribution 39.

[Satellite signal continuity determination unit 27]
When a satellite signal prediction error distribution 39 is recorded in the satellite signal prediction result DB 25, the satellite signal continuity determination unit 27 detects the continuity of the pseudorange 7 and carrier phase 8 described in the satellite signal 10 received by the GNSS antenna 29 based on the satellite signal prediction error distribution 39, and determines the continuity of the satellite signal.

The process steps for the satellite signal continuity determination unit 27 to detect the continuity of the pseudorange 7 and carrier phase 8 will be described below with reference to the flowchart shown in FIG. 14.

Figure 14 shows a process that is inserted between steps S305 and S307 in the flowchart of Figure 9 as an alternative to S306, and can be realized by a processor included in the satellite signal continuity determination unit 27 executing a computer program.

In step S313, the satellite signal continuity determination unit 27 checks whether or not the satellite signal prediction error distribution 39 is recorded in the satellite signal prediction result DB 25. If the satellite signal prediction error distribution 39 is recorded in the satellite signal prediction result DB 25, the process proceeds to step S314. If the satellite signal prediction error distribution 39 is not recorded in the satellite signal prediction result DB 25, the process proceeds to step S315.

In step S314, the satellite signal continuity determination unit 27 calculates a carrier phase prediction error threshold ε1_MAX, which is a threshold for determining whether the carrier phase 8 for the positioning satellite S described in the satellite signal 10 in step S304 has been accurately predicted, based on the satellite signal prediction error distribution 39 recorded in the satellite signal prediction result DB 25. The carrier phase prediction error threshold ε1_MAX may be set to, for example, a value in the 1σ, 2σ, or 3σ interval of the satellite signal prediction error distribution 39, and when the carrier phase prediction error ε1 calculated in step S305 exceeds the threshold, it may be determined that the carrier phase 8 for the positioning satellite S has not been accurately predicted.

In step S315, the satellite signal continuity determination unit 27 calculates a carrier phase prediction error threshold ε1_MAX, which is a threshold for determining whether the carrier phase 8 for the positioning satellite S described in the satellite signal 10 in step S304 has been accurately predicted, based on the correction signal prediction error distribution 37 recorded in the correction signal prediction result DB 24.

[Arithmetic and control unit 28]
The calculation control unit 28 calculates stationary state information 15 of the GNSS antenna 29 according to the satellite signal continuity information 16 acquired from the satellite signal continuity determination unit 27. Then, when the calculation control unit 28 calculates the stationary state information 15 as "stationary", it transmits satellite signals 10 to the satellite signal prediction result DB 25, thereby instructing the satellite signal prediction error distribution 39 to be calculated. The operation of the calculation control unit 28 instructing the satellite signal prediction result DB 25 to perform a calculation is executed immediately after step 205 shown in FIG.

With the above-described configuration, in Example 2, the mobile positioning device 2 can calculate the prediction accuracy of the satellite signal prediction information 19 when the GNSS antenna 29 is stationary, and can calculate an appropriate prediction error threshold based on the prediction error distribution.

As a result, the mobile positioning device 2 can determine the continuity of the satellite signal 10 with high accuracy, improving the accuracy of stationary determination.

In other words, according to the second embodiment of the present invention, it is possible to realize a mobile positioning device and a mobile positioning method that have a simple configuration, improve the accuracy of determining that a mobile station is stationary, and determine the stationary state of a mobile station without relying on the detection accuracy of an inertial sensor.

Instead of using the satellite signal prediction result DB 25, the satellite signal prediction unit 26 can calculate the difference between the satellite signal 10 received from the calculation control unit 28 and a prediction value (prediction model) predicted from the satellite signal prediction information 19, and calculate a satellite signal prediction error distribution 39, which is a probability distribution of the satellite signal prediction error 38, from the calculated difference. The satellite signal prediction unit 26 can then calculate the satellite signal prediction accuracy from the satellite signal prediction error distribution 39. When the mobile station is in a stationary state, the satellite signal prediction unit 26 calculates the satellite signal prediction accuracy based on the stationary state information 15. The satellite signal continuity determination unit 27 then determines the continuity of the satellite signal based on the satellite signal prediction accuracy.

In addition, in this specification, a mobile station is a moving object (e.g., an automobile, a train, an agricultural machine, or a construction machine) equipped with a GNSS antenna 29. In addition, the GNSS antenna 29 shown in FIG. 1 includes a moving object equipped with a GNSS antenna 29, that is, a mobile station.

1: Stationary state determination system, 2: Mobile positioning device, 3: Positioning satellite, 4: Base station, 5: Distribution server, 7: Pseudo distance, 8: Carrier wave phase, 10: Satellite signal, 11: Correction signal, 12: Position information, 13: Approximate position data, 15: Stationary state information, 16: Satellite signal continuity information, 18: Correction signal prediction information, 19: Satellite signal prediction information, 20: Positioning calculation unit, 21: Communication unit, 22: Correction signal DB (correction signal recording unit), 23: Correction signal prediction unit, 24: Correction signal prediction result DB, 25: Satellite signal prediction result DB, 26: Satellite signal prediction unit, 27: Satellite signal continuity determination unit, 28: Calculation control unit, 29: GNSS antenna (mobile station)

Claims (15)

a satellite signal prediction unit that calculates satellite signal prediction information including a satellite signal received by a mobile station and a prediction model of the satellite signal to be distributed at the current time or in the future based on a correction signal based on the satellite signal distributed from a base station;
a satellite signal continuity determination unit that calculates satellite signal continuity information, which is information regarding the continuity of the satellite signal, based on the satellite signal and the satellite signal prediction information;
an arithmetic and control unit that determines a stationary state of the mobile station based on the satellite signal continuity information;
Equipped with
The mobile positioning device, wherein the calculation control unit determines that the mobile station is stationary when the continuity of the satellite signal is detected based on the satellite signal continuity information. 2. The mobile positioning device according to claim 1,
The mobile positioning device, wherein the arithmetic and control unit calculates stationary state information indicating a stationary state of the mobile station. 2. The mobile positioning device according to claim 1,
A correction signal prediction unit is further provided,
the correction signal prediction unit calculates correction signal prediction information including a prediction model of the correction signal to be distributed by the base station at the current time or in the future from the correction signal received in the past;
The mobile positioning device, wherein the satellite signal prediction unit calculates the satellite signal prediction information by correcting the corrected signal prediction information with the satellite signal based on the satellite signal and the corrected signal prediction information. 3. The mobile positioning device according to claim 2,
The mobile positioning device is characterized in that the satellite signal prediction unit calculates a satellite signal prediction error distribution from the difference between the output value of the prediction model of the satellite signal prediction information and the satellite signal, and calculates the satellite signal prediction accuracy. 5. The mobile positioning device according to claim 4,
The mobile positioning device according to claim 1, wherein the satellite signal prediction unit calculates the satellite signal prediction accuracy based on the stationary state information when the mobile station is in a stationary state. 6. The mobile positioning device according to claim 5,
The mobile positioning device, wherein the satellite signal continuity determination unit determines the continuity of the satellite signals based on the satellite signal prediction accuracy. 2. The mobile positioning device according to claim 1,
A mobile positioning device, wherein the satellite signal and the correction signal include at least a carrier phase. 2. The mobile positioning device according to claim 1,
A mobile object positioning device further comprising a correction signal recording unit which records the correction signal in accordance with an instruction from the arithmetic control unit. Calculating satellite signal prediction information including a satellite signal received by the mobile station and a prediction model of the satellite signal to be distributed at the current time or in the future based on a correction signal based on the satellite signal distributed from the base station;
calculating satellite signal continuity information, which is information regarding the continuity of the satellite signal, based on the satellite signal and the satellite signal prediction information;
A mobile positioning method, comprising: determining that the mobile station is stationary when continuity of the satellite signals is detected based on the satellite signal continuity information. The mobile object positioning method according to claim 9,
A mobile positioning method, comprising the steps of: when it is determined that the mobile station is in a stationary state, calculating stationary state information indicative of the stationary state, and transmitting the information to an external terminal. The mobile object positioning method according to claim 9,
Calculating correction signal prediction information including a prediction model of the correction signal to be distributed by the base station at the current time or in the future from the correction signal received in the past;
A mobile positioning method, comprising: calculating the satellite signal prediction information based on the satellite signal and the corrected signal prediction information, by correcting the corrected signal prediction information with the satellite signal. The mobile object positioning method according to claim 10,
A mobile positioning method, comprising: calculating a satellite signal prediction error distribution from a difference between an output value of a prediction model of the satellite signal prediction information and the satellite signal; and calculating satellite signal prediction accuracy. The mobile object positioning method according to claim 12,
A mobile positioning method, comprising: calculating, based on the stationary state information, the satellite signal prediction accuracy when the mobile station is in a stationary state. The mobile object positioning method according to claim 13,
A mobile positioning method, comprising: determining continuity of the satellite signals based on the satellite signal prediction accuracy. The mobile object positioning method according to claim 9,
A mobile positioning method, wherein the satellite signal and the correction signal include at least a carrier phase.

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