Mobile object positioning device and mobile object positioning method

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

[Technical Field]

[0001] The present invention relates to a mobile object positioning device and a mobile object positioning method. [Background technology]

[0002] Conventionally, there is known a technique for correcting errors in a vehicle position detected by a Global Navigation Satellite System (GNSS), which performs positioning by receiving satellite signals transmitted to Earth from artificial satellites located above the Earth.

[0003] Patent Document 1 discloses a technology for integrating the respective detected positions of a GNSS and an inertial sensor that detects the momentum and attitude change of a moving body as follows.

[0004] "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 calculated as the 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 mean value and variance of the adaptive DR error are updated taking into account the newly calculated adaptive DR error, and if the GNSS output position is within the range of possibility obtained by adding an error ellipse based on the assumed DR position and whose center is a position obtained by shifting the assumed DR position by the mean value of the adaptive DR error, the maximum likelihood error ellipse is calculated based on that; if not, the maximum likelihood error ellipse is calculated based on the assumed DR position." In the vehicle position correction method described above, the vehicle position detected by GNSS is corrected based on the vehicle position and attitude obtained by integrating the vehicle momentum and attitude change calculated from the values ​​measured by the inertial sensor.

[0005] In this method, errors in the inertial sensors gradually accumulate as errors in estimating the vehicle position, so the measurement accuracy of the inertial sensors becomes extremely important, and calibration of these inertial sensors is necessary.

[0006] Furthermore, 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.

[0007] Therefore, determining whether the vehicle is stationary is important for calibrating the inertial sensor, and Patent Document 2 discloses the following technology.

[0008] "A mobile object acceleration / distance estimation circuit comprising an acceleration estimation unit that receives an acceleration signal of a mobile object in a traveling direction, determines whether the mobile object is at rest based on a plurality of signals that detect the rest of the mobile object, measures a bias value included in the traveling direction acceleration signal when the determination of the rest of the mobile object is made, corrects the traveling direction acceleration signal using the measured bias value, and calculates and outputs an estimated acceleration and distance value of the mobile object using the corrected traveling direction acceleration signal and the mobile object speed estimate output by the scale factor / speed estimation unit." Furthermore, Patent Document 3 discloses a technique in which "when the output signal input from the movement detector is within a threshold range, it is determined that the moving object is stationary."

[0009] These techniques can be used to determine when a vehicle is stationary. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 6900341 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-195395 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-242192 Summary of the Invention [Problem to be solved by the invention]

[0011] According to the technology described in Patent Document 2, a plurality of sensors are used to determine whether the vehicle is stationary.

[0012] However, when multiple sensors are used, the configuration of the vehicle-mounted equipment becomes complicated, which becomes an issue.

[0013] Furthermore, according to the technology described in Patent Document 3, a stationary state is determined based on the magnitude of the momentum and posture change detected by an inertial sensor.

[0014] However, when an inertial sensor with low detection accuracy is used, there is a problem in that the accuracy of determining the stationary state also becomes low.

[0015] The object of the present invention is to realize a mobile positioning device and a mobile positioning method that have a simple configuration and that 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. [Means for solving the problem]

[0016] In order to achieve the above object, the present invention is configured as follows.

[0017] In a mobile positioning device, the current time or future time is calculated based on the correction signal from the satellite signal transmitted from the base station. Multiple a satellite signal prediction unit that calculates satellite signal prediction information including a prediction model that predicts a satellite signal that will be transmitted from a positioning satellite and received by a mobile station; a satellite signal continuity determination unit that calculates satellite signal continuity information that is information about the continuity of the satellite signal that will be transmitted from the positioning satellite 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; and correction signal prediction information that includes a prediction model of the correction signal that will be distributed by the base station at the current time or in the future based on the correction signal that was received in the past. and correction signal prediction error distribution a correction signal prediction unit that calculates and outputs The satellite signal prediction information from the satellite signal prediction unit and a calculation instruction for the satellite signal prediction error distribution from the calculation control unit Based on The difference between the satellite signal received from the calculation control unit and a predicted value predicted from the satellite signal prediction information is calculated as a satellite signal prediction error, and the calculated satellite signal prediction error is received and recorded to calculate a satellite signal prediction error distribution, which is a probability distribution of the satellite signal prediction error. and a corrected signal prediction result DB, wherein the satellite signal continuity determination unit confirming whether the total number of the plurality of positioning satellites is equal to or greater than a certain number that allows interferometric positioning, and if equal to or greater than the certain number, calculating, for each of the plurality of positioning satellites, a predicted value of a carrier phase of the satellite signal related to the positioning satellite that is included in the satellite signal, and calculating a carrier phase prediction error that is the difference between the predicted value and an actual measured value of the carrier phase;When the satellite signal prediction error distribution is recorded in the correction signal prediction result DB, based on the satellite signal prediction error distribution, Multiple For the positioning satellite The aforementioned calculating a carrier phase prediction error threshold value for determining whether the carrier phase is accurately predicted; and if the satellite signal prediction error distribution is not recorded in the correction signal prediction result DB, calculating a carrier phase prediction error threshold value for determining whether the carrier phase is accurately predicted; Multiple For the positioning satellite The aforementioned calculating the carrier phase prediction error threshold for determining whether the carrier phase is accurately predicted; The aforementioned It is determined whether the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, and if the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, the continuity of the carrier phase is lost. The positioning satellite of Count as a number , ren Continuity was lost The positioning satellite of If the number is less than the threshold for the number of positioning satellites, it is determined that there is continuity of the satellite signal, and if continuity is lost, The positioning satellite of If the number is equal to or greater than the threshold number of positioning satellites, it is determined that there is no continuity of the satellite signals; Output the satellite signal continuity information do.

[0018] Furthermore, in a mobile positioning method, based on a correction signal from a satellite signal distributed from a base station, satellite signal prediction information is calculated including a prediction model that predicts a satellite signal that will be transmitted from a positioning satellite at the current time or in the future and received by a mobile station; based on the satellite signal transmitted from the positioning satellite and the satellite signal prediction information, satellite signal continuity information that is information regarding the continuity of the satellite signal transmitted from the positioning satellite is calculated, and based on the satellite signal transmitted from the positioning satellite and the satellite signal prediction information, a stationary state of the mobile station is determined based on the satellite signal continuity information; based on the correction signal received in the past, correction signal prediction information is calculated including a prediction model of the correction signal that will be distributed by the base station at the current time or in the future, and output; and recording the correction signal prediction information and correction signal prediction error distribution in a correction signal prediction result DB. calculating a predicted value of a carrier phase of the satellite signal related to the positioning satellite, which is included in the satellite signal; and calculating a carrier phase prediction error, which is a difference between the predicted value and an actual measured value of the carrier phase;If a satellite signal prediction error distribution is recorded in the correction signal prediction result DB, a carrier phase prediction error threshold is calculated based on the satellite signal prediction error distribution to determine whether the carrier phase for the positioning satellite is accurately predicted in the satellite signal; It is confirmed whether the total number of the plurality of positioning satellites is equal to or greater than a certain number that allows for interferometric positioning, and if it is equal to or greater than the certain number, for each of the plurality of positioning satellites, If the satellite signal prediction error distribution is not recorded in the correction signal prediction result DB, calculate the carrier phase prediction error threshold based on the correction signal prediction error distribution to determine whether the carrier phase for the positioning satellite is accurately predicted; The aforementioned It is determined whether the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, and if the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, the continuity of the carrier phase is lost. The positioning satellite of counting the number of satellites for which continuity has been lost, and when all of the positioning satellites have been selected, if the number of satellites for which continuity has been lost is less than a threshold value for the number of positioning satellites, determining that there is continuity of the satellite signals, and if the number of satellites for which continuity has been lost is equal to or greater than the threshold value for the number of positioning satellites, determining that there is no continuity of the satellite signals; Output the satellite signal continuity information do. [Effects of the Invention]

[0019] According to the present invention, it is possible to realize a mobile positioning device and a mobile positioning method that have a simple configuration and that determine the stationary state of a mobile station without relying on the detection accuracy of an inertial sensor. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram illustrating a hardware configuration of a stationary state determination system having a mobile body positioning device according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing a correction signal recorded in a correction signal DB. [Figure 3] 10A and 10B are diagrams illustrating pseudoranges and carrier phases calculated by a correction signal prediction unit as correction signal prediction information. [Figure 4]10 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. [Figure 5] 1. FIG. 4 is a diagram showing a correction signal prediction error, which is the difference between a correction signal received from the calculation control unit in FIG. 1 and a predicted value predicted from correction signal prediction information. [Figure 6] 2 is a diagram showing a distribution of correction signal prediction errors calculated from correction signal prediction errors in the correction signal prediction result DB of FIG. 1. FIG. [Figure 7] 10 is a diagram showing a mathematical model relating to a pseudorange and a carrier wave phase calculated by a satellite signal prediction unit as satellite signal prediction information. FIG. [Figure 8] 10 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. [Figure 9] 10 is a flowchart showing the processing of a satellite signal continuity determination unit. [Figure 10] 2 is a diagram showing the data configuration of position information and stationary state information output by the calculation control unit of FIG. 1. [Figure 11] 10 is a flowchart showing the processing of the mobile positioning device. [Figure 12] 10 is a flowchart showing the processing of the mobile positioning device. [Figure 13] 10 is a flowchart showing the processing of the mobile positioning device. [Figure 14] 10 is a flowchart showing a processing procedure for detecting the continuity of a satellite signal by a satellite signal continuity determination unit in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of a stationary state determination system for a mobile station and a determination method therefor 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 explanations will be omitted.

[0022] 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]

[0023] Example 1 A stationary state determination system 1 having a mobile body positioning device 2 according to the present invention is a system used to determine the stationary state of a mobile body such as an automobile, a train, an agricultural machine, or a construction machine.

[0024] FIG. 1 is a diagram illustrating a hardware configuration of a stationary state determination system 1 having a mobile object positioning device 2 according to a first embodiment.

[0025] 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.

[0026] [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 by using the received multiple satellite signals 10, the GNSS antenna 29 can obtain its own position on Earth. The satellite signals 10 contain 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 GNSS redundancy.

[0027] Although the positioning system 1 according to the first embodiment is described as using satellite signals 10 in a single frequency band, the present invention can also be applied to a positioning system that uses satellite signals 10 in multiple frequency bands.

[0028] [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 have been measured with high accuracy in advance, and this position information is stored in the distribution server 5.

[0029] [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 using the RRS method. The RRS method generates the correction signal 11 from the satellite signal 10 received by a base station 4 located near the position based on generated position information 30 (described later) acquired from the positioning device 2 (described later).

[0030] 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.

[0031] Although the stationary state determination system 1 according to the first embodiment is described as using the RRS system as the distribution server 5, the present invention can also be applied to a stationary state determination system 1 using the VRS system as the distribution server 5.

[0032] The distribution server 5 may be a paid service provided by a company other than the manufacturer of the mobile positioning device 2, such as a communication carrier. The distribution server 5 and the positioning device 2 can communicate bidirectionally via a network using a wireless communication line or other known wireless communication lines.

[0033] The distribution server 5 may transmit a new correction signal 11 to the mobile positioning device 2 in accordance with the generated position 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 position information 30 acquired from the mobile positioning device 2, generates a correction signal 11 using the satellite signal 10 received from that base station 4, and transmits the correction signal 11 to the mobile positioning device 2.

[0034] 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 base station 4 selected according to the generated position information 30 acquired from the mobile positioning device 2 is changed. Therefore, the mobile positioning device 2 can detect a change in the base station 4 based on whether the base station ID 102 (see FIG. 2) included in the correction signal 11 received from the distribution server 5 has changed.

[0035] The distribution server 5 calculates a pseudorange 7 (see FIG. 2) and a 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 pseudorange 7 and the carrier phase 8. The pseudorange 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 pseudorange 7 includes a receiver clock error, a satellite clock error, an ionospheric delay, a tropospheric delay, and other noise.

[0036] The carrier wave 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 wave phase 8 includes integer bias, receiver clock error, satellite clock error, ionospheric delay, tropospheric delay, and other noise.

[0037] The carrier phase 8 may be expressed 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 reciprocal of the wavelength of the satellite signal 10. The correction signal 11 includes at least the pseudorange 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.

[0038] [Mobile positioning device 2] The mobile positioning device 2 calculates stationary state information 15 that indicates the stationary state of the GNSS antenna 29 based on the satellite signals 10 received using the GNSS antenna 29 and the correction signals 11 acquired from the distribution server 5. The mobile positioning device 2 also calculates position information 12 that indicates the position of the GNSS antenna 29 based on the satellite signals 10 received using the GNSS antenna 29 and the correction signals 11 acquired from the distribution server 5.

[0039] 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.

[0040] 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, an arithmetic control unit 28, and a GNSS antenna 29.

[0041] The positioning calculation unit 20, communication unit 21, correction signal DB 22 (correction signal recording unit), correction signal prediction unit 23, correction signal prediction result DB 24, satellite signal prediction unit 26, satellite signal prediction result DB 25, and satellite signal continuity determination unit 27 perform processing determined in accordance with the operation command of the calculation control unit 28.

[0042] The calculation control unit 28 outputs the position information 12 and the stationary state information 15 in accordance with the operation cycle of the positioning calculation unit 20. Note that 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 a separate, independent device, such as an external device or an external server. In this case, it is preferable that each element of the mobile positioning device 2 is configured to be able to communicate with each other.

[0043] [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 digital satellite signals 10 to the positioning calculation unit 29.

[0044] The GNSS antenna 29 is installed at a location on the object to be positioned where it is desired to acquire the position. For example, when 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.

[0045] [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.

[0046] The approximate position data 13 is the approximate position of the GNSS antenna 29 calculated by the positioning calculation unit 20 using 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.

[0047] The positioning calculation unit 20 calculates one or more of approximate position data 13 and precise position data 14 by calculating 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.

[0048] 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 carrier wave delays that occur when passing through the ionosphere and troposphere.

[0049] In interferometric positioning, the positioning calculation unit 20 calculates precise position data 14 based on both the satellite signals 10 received by the GNSS antenna 29 and the correction signals 11 received from the calculation control unit 28. In interferometric positioning, the precise position data 14 is calculated from the pseudoranges 7 and carrier phases 8 between the GNSS antenna 29 and at least five or more positioning satellites 3 contained in the satellite signals 10 received by the GNSS antenna 29, and the pseudoranges 7 and carrier phases 8 between the base station 4 and at least five or more positioning satellites 3 contained in the correction signals 11.

[0050] Furthermore, 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, which indicates which part of the continuous wave the carrier phase 8 of the satellite signal 10 is, is known, but the integer part of the wave number excluding the decimal part of the wave number is unknown. In interferometric positioning, once 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.

[0051] 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.

[0052] Therefore, the positioning calculation unit 20 calculates precise position data 14 by correcting the approximate position data 13, which is the result of standalone 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. In this case, 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.

[0053] 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 was continuous up to that point, 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 fractional part of the continuous wave at the carrier wave 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 fractional part and wave number integer part of the carrier wave phase difference, it determines that the interferometric positioning calculation has failed.

[0054] If the positioning calculation unit 20 can calculate precise position data 14, it outputs the precise position data 14 as position information 12, and only if it cannot calculate precise position data 14, it outputs approximate position data 13 as position information 12. The positioning calculation unit 20 outputs the position information 12 to the calculation control unit 28.

[0055] [Communications Department 21] The communication unit 21 transmits the generated position information region received from the calculation and 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) that is the identification number of the positioning satellite 3, a correction signal generation time 101 (see FIG. 2) that is the time when the correction signal 11 was generated, a base station ID 102, a pseudorange 7, and a carrier phase 8. The communication unit 21 outputs the correction signal 11 received from the distribution server 5 to the calculation and control unit 28. The communication unit 21 may fail to receive the correction signal 11, for example, if there is radio interference or a problem occurs in either the communication unit 21 or the distribution server 5.

[0056] [Correction signal DB22] The correction signal DB 22 records the correction signal 11 in accordance with instructions 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 correction signals 11 previously received from the calculation control unit 28. The correction signal DB 22 acquires, from the calculation control unit 28, the correction signal 11 that the calculation control unit 28 received from the distribution server 5 via the communication unit 21, and stores the correction signal 11.

[0057] FIG. 2 is a diagram showing a data table showing details of the correction signal 11 recorded in the correction signal DB 22.

[0058] 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 for the same time and from the same positioning satellite 3 as the correction signal 11 received from the calculation control unit 28 has already been recorded, the correction signal DB 22 updates the pseudorange 7, carrier phase 8, and base station ID 102 of the recorded correction signal 11.

[0059] 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 the correction signal generation time 101 of "07:30:00" corresponds to the latest correction signal 11.

[0060] The correction signal DB 22 is configured in a state where the correction signal prediction unit 23 and the calculation control unit 28 can always refer to the correction signal 11. If the correction signal DB 22 cannot secure a sufficient storage area, for example, it may record the correction signal 11 for only a predetermined fixed period and execute a process of deleting the oldest record when the recording time exceeds the fixed period. 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.

[0061] [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.

[0062] The correction signal prediction unit 23 constructs a mathematical model for predicting the pseudorange 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 will be referred to as "t".

[0063] 3 is a diagram showing a mathematical model for the pseudorange 7 and carrier phase 8 calculated by the correction signal prediction unit 23 as correction signal prediction information 18. FIG. 3 is a graph of the mathematical model. As shown in FIG. 3, the correction signal prediction information 18 is expressed by a mathematical model calculated using values ​​of the pseudorange 7 and carrier phase 8 at a preset number of times, for example, at the past five times recorded in the correction signal DB 22.

[0064] 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, 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).

[0065]

number

[0066]

number

[0067]

number

[0068] The "T" in the above formula (2) will be explained later.

[0069] Based on the correction signal DB 22 and the calculation control unit 28, 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, and calculates the correction signal prediction information 18.

[0070] FIG. 4 is a diagram showing parameters of a mathematical model calculated by the correction signal prediction unit 23 as the correction signal prediction information 18 based on the correction signal DB 22.

[0071] The correction signal prediction unit 23 calculates parameters of a mathematical model that predicts the pseudorange 7 and carrier phase 8 of each positioning satellite 3 at time t as correction signal prediction information 18. For example, when the correction signal DB 22 has recorded the pseudorange 7 and carrier phase 8 of a specific positioning satellite 3 at the past five or more times, the correction signal prediction unit 23 calculates the correction signal prediction information 18 corresponding to the positioning satellite 3.

[0072] 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.

[0073] 5 , the correction signal prediction unit 23 calculates the difference between the correction signal 11 received from the calculation control unit 28 and a prediction value predicted from the correction signal prediction information 18 as a 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 it receives the correction signal 11 from the calculation control unit 28, or may set a control period of 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.

[0074] [Corrected 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 errors 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 errors 36.

[0075] As a result, if the vertical axis indicates the occurrence probability and the horizontal axis indicates the corrected signal prediction error 36, a graph such as that shown in FIG. 6 can be generated, which represents the corrected signal prediction error distribution 37.

[0076] The corrected signal prediction result DB 24 calculates and records the corrected signal prediction error distribution 37 for all positioning satellites 3 for which the corrected signal prediction information 18 was calculated. The corrected 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 corrected signal prediction information 18 and the corrected signal prediction error distribution 37.

[0077] 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 more, the correction signal prediction result DB24 may perform a process of deleting the correction signal prediction information 18 and correction signal prediction error distribution 37 linked to the positioning satellite 3 recorded in the correction signal prediction result DB24.

[0078] Furthermore, 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 the positioning satellites 3 that have been recorded.

[0079] [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 the correction signal 11 based on the satellite signal 10 distributed from the base station 4.

[0080] 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 corrected 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.

[0081] The satellite signal prediction unit 26 constructs a mathematical model (a prediction model of the satellite signal 10 to be delivered at the current time or in the future) for predicting the satellite signal 10 that will next be 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.

[0082] Hereinafter, in this specification, the time written on the satellite signal 10 received by the satellite signal prediction unit 26 from the calculation control unit 28 will be referred to as "T".

[0083] Fig. 7 shows a mathematical model for the pseudorange 7 and carrier phase 8 calculated by the satellite signal prediction unit 26 as satellite signal prediction information 19. Fig. 7 is a graph of the mathematical model.

[0084] As shown in FIG. 7, 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):

[0085]

number

[0086] 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 equation (4), and calculates satellite signal prediction information 19 using the following equation (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".

[0087]

number

[0088] That is, based on the satellite signal 10 and the corrected signal prediction information 18 , the satellite signal prediction unit 26 calculates the satellite signal prediction information 19 by correcting the corrected signal prediction information 18 with the satellite signal 10 .

[0089] The satellite signal prediction unit 26 outputs the calculated satellite signal prediction information 19 to the satellite signal prediction result DB 25 .

[0090] [Satellite signal prediction result DB25] Satellite signal prediction result DB 25 records satellite signal prediction information 19 of positioning satellites 3 based on the outputs of satellite signal prediction unit 26 and calculation control unit 28. Satellite signal prediction result DB 25 records satellite signal prediction information 19 in the format shown in Fig. 8. Satellite signal prediction result DB 25 is configured to allow satellite signal continuity determination unit 27 to refer to satellite signal prediction information 19.

[0091] 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 longer, the satellite signal prediction result DB 25 may execute a process to delete the satellite signal prediction information 19 associated with the positioning satellite 3 that is recorded in the satellite signal prediction result DB 25. Furthermore, 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 the positioning satellites 3 that have been recorded.

[0092] [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. Based on information from the correction signal prediction result DB 24, the satellite signal prediction result DB 25, and the calculation control unit 28, the satellite signal continuity determination unit 27 detects the continuity of the pseudorange 7 and the carrier phase 8 described in the satellite signal 10 received by the GNSS antenna 29, 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.

[0093] 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. Hereinafter, in this 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 to the case where the pseudo distance 7 is used.

[0094] Fig. 9 is a flowchart showing the processing of satellite signal continuity determination unit 27. The flowchart shown in Fig. 9 shows the processing performed by satellite signal continuity determination unit 27 after satellite signal 10 is received from arithmetic control unit 28.

[0095] 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.

[0096] In step S302, S_SUM, which is the total number of positioning satellites 3 described in the satellite signal 10 received from the arithmetic control unit 28, is calculated.

[0097] 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.

[0098] In step S303, if S_SUM is less than 5, the process proceeds to step S310.

[0099] 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 relating 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.

[0100] In step S305, a carrier phase prediction error ε1, which is the difference between the predicted value of carrier phase 8 calculated in step S304 and the actual measured value of carrier phase 8 contained in satellite signal 10 received from arithmetic control unit 28, is calculated.

[0101] 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.

[0102] The carrier phase prediction error threshold ε1_MAX may be, for example, set to the 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, it may be determined that the carrier phase 8 for the positioning satellite S has not been accurately predicted.

[0103] 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. If the carrier phase prediction error ε1 is equal to or greater than ε1_MAX in step S307, the number of satellites for which the continuity of the carrier phase 8 has been lost is counted as N (step S307a), and the process proceeds to step S308. If the carrier phase prediction error ε1 is less than the carrier phase prediction error threshold ε1_MAX in step S307, no specific processing is performed and the process proceeds to step S308.

[0104] In step S308, it is determined whether or not all of the positioning satellites 3 described in the satellite signal 10 received from the arithmetic 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.

[0105] In step S308, if all positioning satellites 3 have not been selected, the next positioning satellite 3 is selected as S (step S308a), and the process returns to step S304.

[0106] 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.

[0107] The positioning satellite number threshold N_MAX may be determined, for example, 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.

[0108]

number

[0109] In step S310 shown above, satellite signal continuity determination section 27 does not output satellite signal continuity information 16 of satellite signal 10 received from arithmetic and control section 28 to arithmetic and control section 28.

[0110] In step S311, satellite signal continuity determination unit 27 outputs satellite signal continuity information 16 to calculation control unit 28, stating that there is no continuity in satellite signal 10 received from calculation control unit 28.

[0111] In step S312, satellite signal continuity determination unit 27 outputs satellite signal continuity information 16 to calculation control unit 28, indicating that there is continuity in satellite signal 10 received from calculation control unit 28.

[0112] [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.

[0113] The arithmetic and control unit 28 calculates stationary state information 15 indicating 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. Then, the arithmetic and control unit 28 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 and attitude estimation system, a vehicle control module, an inertial sensor calibration module, etc. that require the position information 12 and stationary state information 15 of the mobile body correspond to the external terminal.

[0114] 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 therefor, will be described later.

[0115] 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 position information 12. When the calculation control unit 28 has acquired the correction signal 11 from the distribution server 5 via the communication unit 21, the calculation control unit 28 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 position information 12.

[0116] The calculation and 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 used by the distribution server 5 to select the base station 4 that will generate the correction signal 11, and is recorded in the calculation and control unit 28. The distribution server 5 selects the base station 4 that will generate the correction signal 11 according to the position information 12 received from the calculation and control unit 28.

[0117] 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.

[0118] 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 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 satellite signal prediction information 19.

[0119] 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 satellite signal continuity information 16 .

[0120] The calculation control unit 28 outputs the position information 12 and the 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, to the position information 12 and stationary state information 15 calculated using the satellite signal 10, and transmits the linked information to an external terminal (not shown).

[0121] For ease of explanation, Figure 10 lists the output time 103, location information 12, and stationary state information 15 in table format, but the calculation control unit 28 does not transmit the location information 12 and stationary state information 15 at multiple output times all at once. Rather, it links the location 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 to an external terminal (not shown) each time.

[0122] Calculation control unit 28 receives satellite signal continuity information 16 from satellite signal continuity determination unit 27, and calculates stationary state information 15. When calculation control unit 28 receives satellite signal continuity information 16 indicating that there is continuity, it outputs stationary state information 15 to the external terminal as indicating stationary, as shown in FIG.

[0123] When the calculation control unit 28 receives the satellite signal continuity information 16 indicating no continuity, it outputs the stationary state information 15 indicating operation to the external terminal, as shown in FIG.

[0124] If the calculation control unit 28 does not receive the satellite signal continuity information 16, it outputs the stationary state information 15 as NULL to the external terminal as shown in FIG.

[0125] [Mobile Positioning Device 2 as a whole] Hereinafter, the processing of the mobile object positioning device 2 will be described by explaining the order in which the arithmetic and control unit 28 issues operation commands and the method of determining the order, with reference to FIGS.

[0126] The following process is executed each time the GNSS antenna 29 receives the satellite signal 10 from the positioning satellite 3.

[0127] Fig. 11 is a flowchart showing steps S201 to S207 of the processing of the mobile object positioning device 2. Fig. 12 is a flowchart showing steps S208 to S217 of the processing of the mobile object positioning device 2. Fig. 13 is a flowchart showing steps S218 to S232 of the processing of the mobile object positioning device 2.

[0128] 11, in step S201, the GNSS antenna 29 transmits the satellite signal 10 received from the positioning satellite 3 to the calculation control unit .

[0129] 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 it to perform calculations. The satellite signal continuity determination unit 27 executes the processes from step S301 to step S312 shown in FIG.

[0130] In step S203, calculation control unit 28 checks whether it has received satellite signal continuity information 16 from satellite signal continuity determination unit 27. If it has received satellite signal continuity information 16, it proceeds to step S204. If it has not received satellite signal continuity information 16 in step S203, it proceeds to step S207.

[0131] In step S204, calculation control unit 28 checks whether satellite signal continuity information 16 received from satellite signal continuity determination unit 27 states "continuity exists." If satellite signal continuity information 16 states "continuity exists," the process proceeds to step S205. If satellite signal continuity information 16 does not state "continuity exists," the process proceeds to step S206.

[0132] In step S205, the calculation control unit 28 calculates the stationary state information 15 as "stationary."

[0133] In step S206, the calculation control unit 28 calculates the stationary state information 15 as "motion."

[0134] In step S207, the calculation control unit 28 calculates the stationary state information 15 as "NULL".

[0135] Next, in step S208 of Fig. 12, it is confirmed whether or not the calculation control unit 28 has recorded the generated position information 30. If the calculation control unit 28 has recorded the generated position information 30, the process proceeds to step S209. If the calculation control unit 28 has not recorded the generated position information 30 in step S208, the process proceeds to step S227 (shown in Fig. 13).

[0136] In step S209, the calculation control unit 28 transmits the generated position information 30 to the communication unit 21.

[0137] In step S210, the communication unit 21 transmits the generated position information 30 received from the calculation control unit 28 to the distribution server 5, thereby receiving the correction signal 11 from 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.

[0138] 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).

[0139] 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).

[0140] 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.

[0141] In step S214, the calculation control unit 28 deletes the correction signal 11 recorded in the correction signal DB22, thereby initializing the correction signal DB22.

[0142] 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.

[0143] In step S216, the calculation control unit 28 deletes the satellite signal prediction information 19 recorded in the satellite signal prediction result DB 25, thereby initializing the satellite signal prediction result DB 25.

[0144] In step S217, the calculation control unit 28 transmits an initialization command to the positioning calculation unit 20, thereby initializing the positioning calculation of the positioning calculation unit 20.

[0145] 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 perform processing. Thereafter, 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.

[0146] In step S219, calculation control unit 28 transmits satellite signal 10 received from GNSS antenna 29 in step S201 to satellite signal prediction unit 26 and commands satellite signal prediction unit 26 to perform processing. Thereafter, satellite signal prediction unit 26 transmits satellite signal prediction information 19 to satellite signal prediction result DB 25, and satellite signal prediction result DB 25 records satellite signal prediction information 19.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] In step S226, the calculation control unit 28 commands the positioning calculation unit 20 to perform interferometric positioning.

[0154] In step S227, the calculation control unit 28 commands the positioning calculation unit 20 to perform independent positioning.

[0155] In step S228, the calculation control unit 28 determines whether the positioning calculation unit 20 has succeeded in interferometric positioning. Here, the calculation control unit 28 determines 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 wave 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.

[0156] In step S229, the positioning calculation unit 20 calculates precise position data 14 by correcting the standalone positioning result with the interferometric positioning result, and outputs the precise position data 14 to the calculation control unit 28 as position information 12.

[0157] 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 , as the position information 12.

[0158] In step S231, the arithmetic and control unit 28 outputs the position information 12 and the stationary state information 15 to the external terminal.

[0159] In step S232, the calculation control unit 28 records the position information 12 acquired from the positioning calculation unit 20 as generated position information 30, and then ends the process.

[0160] 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 that the GNSS antenna 29 will receive from the positioning satellite 3, and the continuity of the satellite signal 10 received by the GNSS antenna 29 is detected from the discrepancy between the predicted value and the actual measured value.

[0161] If the mobile positioning device 2 detects continuity of the received satellite signals 10, it determines that the GNSS antenna 29 is stationary.

[0162] With this configuration, it becomes possible to determine the stationary state of a moving object using only GNSS without installing an attitude measurement device or the like, thereby simplifying the structure.

[0163] According to the first embodiment, the stationary state determination system can determine the continuity of the satellite signals 10 obtained from the positioning satellites 3 and the correction signals obtained from the base stations 4. If the acquired satellite signals 10 are continuous, the stationary state determination system can determine that the vehicle is stationary, which simplifies the configuration and enables stationary state determination without relying on an inertial sensor.

[0164] That is, 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 determine the stationary state of a mobile station without relying on the detection accuracy of an inertial sensor.

[0165] Example 2 Next, a second embodiment of the present invention will be described.

[0166] The mobile positioning device 2 of the present 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 therefore is not shown in the figure.

[0167] The differences between the first and second embodiments will be described below.

[0168] The difference between Example 2 and Example 1 is that when calculation control unit 28 calculates stationary state information 15 as “stationary,” calculation control unit 28 instructs satellite signal prediction result DB 25 to calculate satellite signal prediction error distribution 39, and satellite signal continuity determination unit 27 determines the continuity of satellite signal 10 based on satellite signal prediction error distribution 39 calculated by satellite signal prediction result DB 25, and calculates satellite signal continuity information 16.

[0169] [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.

[0170] Then, satellite signal prediction result DB 25 receives and records the calculated satellite signal prediction errors 38, and calculates satellite signal prediction error distribution 39, which is the probability distribution of satellite signal prediction errors 38. Satellite signal prediction result DB 25 calculates satellite signal prediction error distribution 39 only when instructed by calculation control unit 28 to calculate satellite signal prediction error distribution 39.

[0171] [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.

[0172] Hereinafter, the processing procedure by which the satellite signal continuity determination unit 27 detects the continuity of the pseudorange 7 and the carrier phase 8 will be described with reference to the flowchart shown in FIG.

[0173] FIG. 14 shows processing that is inserted between steps S305 and S307 in the flowchart of FIG. 9 as a substitute for S306, and can be realized by a processor included in the satellite signal continuity determination unit 27 executing a computer program.

[0174] In step S313, satellite signal continuity determination unit 27 checks whether satellite signal prediction error distribution 39 is recorded in satellite signal prediction result DB 25. If satellite signal prediction error distribution 39 is recorded in satellite signal prediction result DB 25, proceed to step S314. If satellite signal prediction error distribution 39 is not recorded in satellite signal prediction result DB 25, proceed to step S315.

[0175] In step S314, satellite signal continuity determination unit 27 calculates carrier phase prediction error threshold ε1_MAX, which is a threshold for determining whether carrier phase 8 for positioning satellite S described in satellite signal 10 in step S304 has been accurately predicted, based on satellite signal prediction error distribution 39 recorded in satellite signal prediction result DB 25. Carrier phase prediction error threshold ε1_MAX may be set to, for example, a value in the 1σ, 2σ, or 3σ interval of satellite signal prediction error distribution 39, and when carrier phase prediction error ε1 calculated in step S305 exceeds the threshold, it may be determined that carrier phase 8 for positioning satellite S has not been accurately predicted.

[0176] In step S315, the satellite signal continuity determination unit 27 calculates the 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 DB24.

[0177] [Calculation 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 by the calculation control unit 28 to instruct the satellite signal prediction result DB 25 to perform calculation is executed immediately after step 205 shown in FIG. 11 .

[0178] 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.

[0179] Therefore, the mobile positioning device 2 can determine the continuity of the satellite signals 10 with high accuracy, and the accuracy of determining whether the mobile positioning device 2 is still can be improved.

[0180] 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 stationary state without relying on the detection accuracy of the inertial sensor, and determine the stationary state of a mobile station.

[0181] Instead of using satellite signal prediction result DB 25, satellite signal prediction unit 26 can calculate the difference between satellite signal 10 received from calculation control unit 28 and a prediction value (prediction model) predicted from satellite signal prediction information 19, and calculate satellite signal prediction error distribution 39, which is a probability distribution of satellite signal prediction error 38, from the calculated difference. Satellite signal prediction unit 26 can then calculate the satellite signal prediction accuracy from satellite signal prediction error distribution 39. When the mobile station is in a stationary state, satellite signal prediction unit 26 calculates the satellite signal prediction accuracy based on stationary state information 15. Satellite signal continuity determination unit 27 then determines the continuity of the satellite signal based on the satellite signal prediction accuracy.

[0182] In this specification and the like, a mobile station is a moving object (for example, an automobile, a train, an agricultural machine, or a construction machine) equipped with a GNSS antenna 29. The GNSS antenna 29 shown in Fig. 1 also includes a moving object equipped with the GNSS antenna 29, that is, a mobile station. [Explanation of symbols]

[0183] 1···Stationary state determination system, 2···Mobile positioning device, 3···Positioning satellite, 4···Base station, 5···Distribution server, 7···Pseudo distance, 8···Carrier phase, 10···Satellite signal, 11···Correction signal, 12···Location 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

1. a satellite signal prediction unit that calculates satellite signal prediction information including a prediction model that predicts satellite signals that will be transmitted from a plurality of positioning satellites at the current time or in the future and received by the mobile station based on a correction signal based on a 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 signals transmitted from the positioning satellites, based on the satellite signals transmitted from the positioning satellites 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; a correction signal prediction unit that calculates and outputs correction signal prediction information and a correction signal prediction error distribution, the 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, based on the correction signal received in the past; a correction signal prediction result DB that calculates, based on the satellite signal prediction information from the satellite signal prediction unit and a calculation instruction for a satellite signal prediction error distribution from the calculation control unit, a difference between the satellite signal received from the calculation control unit and a prediction value predicted from the satellite signal prediction information, as a satellite signal prediction error, and receives and records the calculated satellite signal prediction error, thereby calculating a satellite signal prediction error distribution, which is a probability distribution of the satellite signal prediction error; Equipped with The satellite signal continuity determination unit It is confirmed whether the total number of the plurality of positioning satellites is equal to or greater than a certain number that allows for interferometric positioning, and if it is equal to or greater than the certain number, for each of the plurality of positioning satellites, calculating a predicted value of a carrier phase of the satellite signal related to the positioning satellite, which is included in the satellite signal; and calculating a carrier phase prediction error, which is a difference between the predicted value and an actual measured value of the carrier phase; If the satellite signal prediction error distribution is recorded in the correction signal prediction result DB, a carrier phase prediction error threshold is calculated based on the satellite signal prediction error distribution to determine whether the carrier phases for the plurality of positioning satellites are accurately predicted; If the satellite signal prediction error distribution is not recorded in the correction signal prediction result DB, calculate the carrier phase prediction error threshold based on the correction signal prediction error distribution to determine whether the carrier phases for the multiple positioning satellites are accurately predicted; determining whether the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, and if the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, counting the number of positioning satellites for which the continuity of the carrier phase has been lost; If the number of the positioning satellites for which continuity has been lost is less than a threshold value for the number of positioning satellites, it is determined that there is continuity of the satellite signals, and if the number of the positioning satellites for which continuity has been lost is equal to or greater than the threshold value for the number of positioning satellites, it is determined that there is no continuity of the satellite signals; A mobile positioning device that outputs the satellite signal continuity information.

2. 2. The mobile positioning device according to claim 1, The mobile positioning device, wherein the satellite signal prediction unit calculates the prediction accuracy of the satellite signals when the mobile station is in a stationary state based on a determination of the stationary state of the mobile station.

3. 2. The mobile positioning device according to claim 1, A mobile object positioning device further comprising a correction signal recording unit that records the correction signal in accordance with an instruction from the arithmetic control unit.

4. Calculating satellite signal prediction information including a prediction model that predicts satellite signals that will be transmitted from a plurality of positioning satellites at the current time or in the future and received by the mobile station based on correction signals from satellite signals distributed from the base station; calculating satellite signal continuity information, which is information regarding the continuity of the satellite signals transmitted from the positioning satellites, based on the satellite signals transmitted from the positioning satellites and the satellite signal prediction information; determining a stationary state of the mobile station based on the satellite signal continuity information; Calculating and outputting correction signal prediction information and a correction signal prediction error distribution, the 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; recording the correction signal prediction information and the correction signal prediction error distribution in a correction signal prediction result DB; calculating a predicted value of a carrier phase of the satellite signal related to the positioning satellite, which is included in the satellite signal; and calculating a carrier phase prediction error, which is a difference between the predicted value and an actual measured value of the carrier phase; If a satellite signal prediction error distribution is recorded in the correction signal prediction result DB, a carrier phase prediction error threshold is calculated based on the satellite signal prediction error distribution to determine whether the carrier phase for the positioning satellite is accurately predicted in the satellite signal; It is confirmed whether the total number of the plurality of positioning satellites is equal to or greater than a certain number that allows for interferometric positioning, and if it is equal to or greater than the certain number, for each of the plurality of positioning satellites, If the satellite signal prediction error distribution is not recorded in the correction signal prediction result DB, calculate the carrier phase prediction error threshold based on the correction signal prediction error distribution to determine whether the carrier phases for the multiple positioning satellites are accurately predicted; determining whether the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, and if the carrier phase prediction error is equal to or greater than the carrier phase prediction error threshold, counting the number of positioning satellites for which the continuity of the carrier phase has been lost; If the number of the positioning satellites for which continuity has been lost is less than a threshold value for the number of positioning satellites, it is determined that there is continuity of the satellite signals, and if the number of the positioning satellites for which continuity has been lost is equal to or greater than the threshold value for the number of positioning satellites, it is determined that there is no continuity of the satellite signals; A mobile positioning method, characterized in that the satellite signal continuity information is output.

5. 5. The mobile unit positioning method according to claim 4, A mobile positioning method, comprising: calculating a prediction accuracy of the satellite signal prediction information when the mobile station is in a stationary state based on a determination of the stationary state of the mobile station.

6. 5. The mobile unit positioning method according to claim 4, A mobile object positioning method, characterized in that the correction signal is recorded in a correction signal recording unit.

7. 5. The mobile unit positioning method according to claim 4, A mobile positioning method, wherein the satellite signal and the correction signal include at least the carrier wave phase.

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