JP2023180596A - Positioning system and positioning method in positioning system - Google Patents

Abstract

To prevent a decrease in positioning accuracy immediately after a virtual reference station is generated again in a positioning system using satellite signals.SOLUTION: When a virtual reference station 6 is generated again in a positioning system, the positioning system uses a correction signal 14 received from a distribution server 5 in the past to calculate a predictive model of a pseudo distance and carrier wave phase that will be received from the distribution server 5 at the current time or in the future, and detects the continuity of the correction signal 14 from the correction signal 14 and the pseudo distance described in a correction signal predicted value. When a signal 38 indicating the continuity of the correction signal 14 is received from a pseudo distance continuity detection unit 23, an arithmetic control unit 27 does not change base station identification information of the correction signal 14 received from a communication unit 21.SELECTED DRAWING: Figure 1

Description

The present invention relates to a positioning system and a positioning method in the positioning system.

2. Description of the Related Art Conventionally, interferometric positioning exists as a positioning method using GNSS (Global Navigation Satellite System), which performs positioning by receiving satellite signals transmitted to the earth from artificial satellites located above the earth. In interferometric positioning, for example, the base line length from the known point to the observation point is calculated using the carrier wave phase of the satellite signal received at the observation point and another known point, and the position coordinates of the observation point on the earth are determined.

In interferometric positioning, in addition to the RRS method (Real Reference Station), in which a reference station for observing satellite signals is installed at a known point, a virtual reference station is created at an arbitrary point from satellite signals observed at an electronic reference point, and A VRS method (Virtual Reference Station) has been proposed in which interferometric positioning is performed at a virtual reference station. In the VRS method, a virtual reference station is created near the initial position of the observation point, and the baseline length from the virtual reference station, which is a known point, to the observation point is calculated by calculating the satellite signal that will be received by the virtual reference station. , find the position coordinates of the observation point on the earth. In the RRS method, as the baseline length between the installed reference station and observation point increases, the positioning error due to satellite signals passing through the ionosphere and troposphere increases, but in the VRS method, a virtual reference station is installed as a known point near the observation point. Since it can be generated, it is possible to reduce positioning errors caused by an increase in the baseline length and to calculate the position coordinates of the observation point on the earth with high precision. For example, Patent Document 1 states, “In a VRS (Virtual Reference Station) network type RTK (Real Time Kinematic)-GNSS (Global Navigation Satellite System) survey method, a GNSS surveying device is used to locate a target survey point. installed at the same location. The approximate coordinates of the same point determined by independent positioning are transmitted to the data distribution station as the coordinates of the virtual reference point.''

In a positioning system that uses interferometric positioning to calculate a moving observation point, it is known that the movement of the observation point increases the baseline length with respect to a known point, resulting in a decrease in positioning accuracy at the observation point. For example, Patent Document 2 describes a positioning system that changes the reference station when the baseline length increases and the positioning accuracy in interferometric positioning decreases. a reference station communication unit that receives observation data generated by the reference station receiving radio waves from an artificial satellite from a plurality of reference stations arranged at respective known position coordinates; a correction information creation unit that creates positioning correction information used for position measurement of the positioning target based on observation data; an information storage unit that stores the positioning correction information of each of the plurality of reference stations; a reference station selection unit that acquires approximate position information of a target and selects one or more reference stations located near the positioning target based on the rough position information of the positioning target; A positioning target communication unit that receives observation data received and generated by the positioning target from the positioning target, positioning correction information of the selected one or more reference stations, and the positioning based on the observation data of the positioning target. A configuration is disclosed that includes a position information calculation unit (summary excerpt) that calculates position information of a target.

Patent Publication No. 2016-128771 JP 2021-47054 Publication

According to Patent Document 1 and Patent Document 2, when the positioning accuracy of a virtual reference station generated near the initial position of an observation point using the VRS method decreases due to an increase in the baseline length, a virtual reference station is generated again near the observation point after movement. By doing so, a positioning system that improves positioning accuracy can be realized. In interferometric positioning, the position coordinates of an observation point are determined by assuming that the satellite signal received at a known point is continuous. Therefore, in the VRS method, when a virtual reference station is regenerated, the satellite signal received at a known point Since the assumption that is continuous is rejected, the positioning operation is initialized. When positioning calculations are initialized, positioning accuracy temporarily decreases in interferometric positioning. On the other hand, in the VRS method, even if the baseline length has not increased, when communication between the observation point and the base station is interrupted for a certain period of time, or when a problem occurs in the calculation of the virtual reference station, the calculation of the virtual reference station is stopped and the virtual reference station may be regenerated. In such a case, the positional fluctuation of the regenerated virtual reference station is slight, so the satellite signal received by the virtual reference station is continuous. Therefore, we considered that the positioning system can continue positioning calculations using interferometric positioning without initializing positioning calculations, and investigated the positioning method according to the present invention.

An object of the present invention is to prevent a decrease in positioning accuracy by determining the initialization of positioning calculations based on the continuity of satellite signals in the virtual reference station when a virtual reference station is generated again in a positioning system using satellite signals. An object of the present invention is to realize a positioning system and a positioning method that prevent the above problems and continue calculation.
Another object of the present invention is to predict, in a positioning system using satellite signals, pseudoranges and carrier phases that will be received from a distribution server at the current time or in the future, using correction signals received from a distribution server in the past. The object of the present invention is to realize a positioning system and a positioning method that prevent a decrease in positioning accuracy immediately after a virtual reference station is generated again by calculating a model.

The positioning system of the present invention includes a plurality of positioning satellites, a base station that outputs a correction signal including at least a pseudorange, a carrier phase, and base station identification information according to the position information acquired from the positioning satellites, and a virtual reference station. It consists of a distribution server that provides a correction signal including pseudorange, carrier phase, and base station identification information according to the position information that will be sent, and a positioning device that receives satellite signals from positioning satellites and calculates position information. be done. The positioning device calculates precise position data based on a correction signal provided from a distribution server in addition to rough position data calculated from satellite signals received by a GNSS antenna. Here, the receiving device includes a correction signal prediction unit that calculates correction signal prediction information including a prediction model of at least the pseudorange and carrier phase that will be received by the communication unit at the current time or in the future from the correction signal received in the past. and a pseudorange continuity detection unit that detects the continuity of the correction signal from the correction signal and the pseudorange described in the correction signal prediction information, and the arithmetic control unit is configured such that the pseudorange continuity detection unit detects the continuity of the correction signal. If detected, the positioning calculation for calculating precise position data is continued without changing the base station identification information of the correction signal received from the communication unit.

According to the present invention, even if a virtual reference station is generated again in a positioning system, interferometric positioning calculations can be continued without initializing the positioning calculation, so in an observation system using satellite signals, the virtual reference station It is possible to prevent a temporary decrease in positioning accuracy immediately after the change.

FIG. 1 is a block diagram showing the hardware configuration of a positioning system 1 according to the present invention. 2 is a diagram showing a data structure of a correction signal 14 recorded by a correction signal DB 25 in FIG. 1. FIG. 2 is a diagram showing processing information 106 recorded by the correction signal DB 25 in FIG. 1. FIG. 2 is a diagram showing a mathematical model and equations 1 to 3 regarding the pseudorange and carrier phase calculated as correction signal prediction information 35 by the correction signal prediction unit 22 of FIG. 1. FIG. 3 is a diagram showing parameters of a mathematical model calculated as correction signal prediction information 35 by a correction signal prediction unit 22 based on a correction signal DB 25. FIG. 2 is a diagram showing a correction signal prediction error 36 that is the difference between the correction signal 14 received from the calculation control unit 27 of FIG. 1 and the predicted value predicted from the correction signal prediction information 35. FIG. (a) is a diagram showing a correction signal prediction error distribution 163 calculated from the correction signal prediction error 36 by the prediction result DB 26 in FIG. 1, and (b) is a calculation formula for the positioning satellite number threshold N_MAX. 2 is a flowchart showing a processing procedure of the pseudorange continuity detection unit 23 of FIG. 1. FIG. 2 is a flowchart showing the processing procedure of the carrier phase correction amount calculation unit 24 of FIG. 1. FIG. It is a flowchart (part 1) which shows the processing procedure of the positioning device 20 of a present example. It is a flowchart which shows the processing procedure of the positioning device 20 of a present Example (part 2). It is a flowchart which shows the processing procedure of the positioning device 20 of a present Example (part 3). 2 is a diagram showing a data structure of positioning state information 170 output by the positioning calculation unit 29 of FIG. 1. FIG. 2 is a flowchart showing a processing procedure for outputting positioning state information 170, which is executed by the arithmetic control unit 27 in FIG. 1. FIG.

Embodiments of the positioning system 1 according to the present invention will be described below with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description 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.

The positioning system 1 according to the present embodiment is used, for example, for fixed point surveying and positioning of position information of low-speed moving objects such as agricultural machines and construction machines. FIG. 1 is a diagram showing the overall hardware configuration of the positioning system 1. As shown in FIG. The positioning system 1 includes a positioning device 20, a plurality of positioning satellites 3, a plurality of base stations 4, and a distribution server 5. The scope of the positioning system 1 of the present invention refers to the entire configuration shown in FIG. 1 as a "positioning system" in a broad sense, but in the claims, the positioning device 20 portion is referred to as a "positioning system" in a narrow sense. .

[Positioning satellite]
The positioning satellite 3 is composed of a plurality of artificial satellites located in a satellite orbit above the earth, and constructs a global navigation satellite system (GNSS) by transmitting a satellite signal 10 toward the ground. GNSS allows the GNSS antenna 28 to obtain its own position on the earth by receiving some of the satellite signals 10 from the plurality of positioning satellites 3 and using the plurality of received satellite signals 10. The satellite signal 10 includes at least the position information of the positioning satellite 3 and a satellite clock error. The positioning satellite 3 transmits satellite signals 10 in multiple frequency bands to provide GNSS redundancy. Although the positioning system 1 according to this embodiment is described as using the satellite signal 10 in a single frequency band, the present invention can be similarly applied to a positioning system using the satellite signal 10 in multiple frequency bands. .

[base station]
A plurality of base stations 4 are installed at different points on the earth, and receive satellite signals 10 transmitted by respective positioning satellites 3. The base station 4 transmits received satellite signals 11 received from a plurality of positioning satellites 3 to a distribution server 5 (details will be described later). All base stations 4 transmit received satellite signals 11 received from positioning satellites 3 to distribution server 5, respectively. The positions of all base stations 4 on the earth have been determined in advance with high precision, and the position information is stored in the distribution server 5.

[Distribution server]
The distribution server 5 receives the received satellite signal 11 from the base station 4 and generates a correction signal 14 using the VRS method. In the VRS method, a virtual reference station 6 is generated at an arbitrary position, and a satellite signal 12 that will be received by the virtual reference station 6 is calculated from a satellite signal 11 received by a base station 4 installed near the virtual reference station 6. do. The distribution server 5 generates a virtual reference station 6 near the position based on the generated position information 108 acquired from the positioning device 20, calculates the correction signal 14, and transmits the correction signal 14 to the positioning device 20. For example, if a calculation error occurs in the virtual reference station 6 and the highly accurate correction signal 14 cannot be delivered to the positioning device 20, the distribution server 5 stops the calculation of the virtual reference station 6. As the distribution server 5, a paid service provided by a company other than the manufacturing company of the positioning device 20, such as a communication carrier, can be used. The distribution server 5 and the positioning device 20 can communicate bidirectionally through a network using a wireless communication line or other known wireless communication line.

After stopping the calculation of the virtual reference station 6, the distribution server 5 generates a new virtual reference station 6' again near the position acquired from the positioning device 20. A virtual reference station ID 101, which is information for identifying each virtual reference station 6, is defined. The distribution server 5 generates a correction signal 14 including the virtual reference station ID 101. The distribution server 5 changes the virtual reference station ID 101 every time it generates the virtual reference station 6 again. Therefore, the positioning device 20 can detect that the virtual reference station 6 has been regenerated based on whether the virtual reference station ID 101 (see FIG. 2) written in the correction signal 14 received from the distribution server 5 has been changed. Note that the distribution server 5 generates a plurality of virtual reference stations 6 at arbitrary positions in advance, and transmits a new correction signal 14 to the positioning device 20 according to the generated position information 108 acquired from the positioning device 20. It's okay. In that case, the distribution server 5 selects the virtual reference station 6 generated closest to the generated position information 108 acquired from the positioning device 20, and transmits a new correction signal 14 calculated as the virtual reference station 6 to the positioning device 20. Send.

The distribution server 5 calculates a pseudorange 7 and a carrier wave phase 8 for each positioning satellite 3 based on the satellite signal 10 that will be received by the virtual reference station 6, and generates a correction signal including the pseudorange 7 and the carrier wave phase 8. 14 is calculated. The pseudorange 7 is the distance between the positioning satellite 3 and the GNSS antenna 28, which is calculated by measuring the time until the satellite signal 10 transmitted from the positioning satellite 3 is received by the GNSS antenna 28. The pseudorange 7 includes receiver clock errors, satellite clock errors, ionospheric delays, tropospheric delays, and other noises.

The carrier wave phase 8 is the phase difference between the phase of the satellite signal 10 transmitted by the positioning satellite 3 and the satellite signal 10 received by the GNSS antenna 28 at the same time. The carrier wave phase 8 includes integer bias, receiver clock error, satellite clock error, ionospheric delay, tropospheric delay, and other noises. The carrier wave phase 8 may be written as a distance component by multiplying the wavelength of the satellite signal 10 transmitted by the positioning satellite 3. In that case, the processing of the positioning device 20 is performed by multiplying the carrier wave phase 8 by the reciprocal of the wavelength of the satellite signal 10. The correction signal 14 includes at least the pseudorange 7 of each positioning satellite 3 in the virtual reference station 6, the carrier wave phase 8, the virtual reference station ID 101, and the position of the virtual reference station 6 on the earth.

[GNSS antenna]
The GNSS antenna 28 receives satellite signals 10 from a plurality of positioning satellites 3 located above the earth, and transmits the received satellite signals 31 to the positioning calculation unit 29. Here, the satellite signal 10 is an analog signal, and the GNSS antenna 28 is configured to A/D convert the received satellite signal 10 and transmit a satellite signal 31 as a digital signal to the positioning calculation unit 29. The GNSS antenna 28 is installed at a location on the object to be measured whose position is desired to be obtained. For example, when the positioning device 20 is used for a moving body, the GNSS antenna 28 may be installed on the vehicle body of the target moving body.

[Positioning device]
The positioning device 20 calculates position information 32 indicating the position of the GNSS antenna 28 based on the satellite signal 10 received using the GNSS antenna 28 and the correction signal 14 acquired from the distribution server 5. The positioning device 20, as shown in FIG. , a prediction result DB (database) 26, and an arithmetic control section 27. The positioning calculation unit 29, the communication unit 21, the correction signal prediction unit 22, the pseudorange continuity detection unit 23, and the carrier phase correction amount calculation unit 24 execute predetermined processing according to the operation command from the calculation control unit 27. do. The calculation control unit 27 outputs position information 32 according to the operation cycle of the positioning calculation unit 29. Note that each element of the positioning device 20 may be configured so that its functions are realized by hardware or by software by executing a computer program. Furthermore, each element of the positioning device 20 does not necessarily need to be configured in a single piece of hardware, and may be configured as separate devices, such as external devices or external servers. In that case, each element of the positioning device 20 may be configured to be able to communicate with each other.

[Positioning calculation unit]
The positioning calculation unit 29 calculates the position of the GNSS antenna 28 on the earth based on the satellite signal 31 from the positioning satellite 3 received from the GNSS antenna 28 and the correction signal 14 received from the calculation control unit 27, and generates approximate position data 32a. and the precise position data 32b. The positioning calculation unit 29 outputs either the calculated rough position data 32a or precise position data 32b to the calculation control unit 27 as position information 32.

The approximate position data 32a is the approximate position of the GNSS antenna 28 calculated by the positioning calculation unit 29 using independent positioning. The precise position data 32b is the precise position of the GNSS antenna 28 calculated by the positioning calculation unit 29 using interferometric positioning. The precise position data 32b is a highly accurate positioning result that is closer to the actual position of the GNSS antenna 28 than the rough position data 32a. The positioning calculation unit 29 calculates the pseudorange 7 and carrier phase 8 for each positioning satellite 3 based on the satellite signal 31 received from the GNSS antenna 28, thereby determining either the approximate position data 32a or the precise position data 32b. Operate on one or more.

In independent positioning, rough position data 32a is calculated based on the plurality of satellite signals 10 received by the GNSS antenna 28. In independent positioning, approximate position data 32a is calculated from the pseudo distances 7 between at least four positioning satellites 3 and the GNSS antenna 28 using the principle of triangulation. The above pseudorange 7 does not include errors caused by the orbit of each positioning satellite 3, the accuracy of the clock used in the positioning device 20 or the positioning satellite 3, the delay of the carrier wave that occurs when passing through the ionosphere or the troposphere, etc. I'm here. Furthermore, when calculating the approximate position data 32a, the positioning calculation unit 29 multiplies the wavelength of the satellite signal 10 transmitted by the positioning satellite 3 by the carrier wave phase 8 calculated from the satellite signal 10 received by the GNSS antenna 28 to obtain a distance component. In this way, the approximate position data 32a may be calculated based on the principle of triangulation.

In interferometric positioning, precise position data 32b is calculated based on both the satellite signal 10 received by the GNSS antenna 28 and the correction signal 14 received from the calculation control unit 27. In interferometric positioning, pseudo distances 7 and carrier wave phases 8 between at least five positioning satellites 3 included in the satellite signal 10 received by the GNSS antenna 28 and the GNSS antenna 28, and at least five or more satellites included in the correction signal 14 Precise position data 32b is calculated from the pseudo distance 7 and carrier phase 8 between the positioning satellite 3 and the virtual reference station 6. In interferometric positioning, a carrier phase difference, which is the difference between the carrier wave phase 8 between the positioning satellite 3 and the GNSS antenna 28 and the carrier wave phase 8 between the positioning satellite 3 and the virtual reference station 6, is calculated. In interferometric positioning, when calculating the carrier phase difference, when the GNSS antenna 28 receives the satellite signal 10, the decimal part of the wave number can be determined in the carrier phase 8 of the satellite signal 10 to determine which part of the continuous wave it is. The integer part of the wave number excluding the fractional part of the wave number is unknown. In interferometric positioning, when this wave number integer part is determined, the baseline length between the virtual reference station 6 and the GNSS antenna 28 can be accurately determined.

In interferometric positioning, since the position of the virtual reference station 6 on the earth is written in the correction signal 14, the position of the GNSS antenna 28 can be predicted from the baseline length between the position of the virtual reference station 6 and the GNSS antenna 28. Therefore, the positioning calculation unit 29 uses the position of the GNSS antenna 28 predicted from the baseline length between the position of the virtual reference station 6 and the GNSS antenna 28 to correct the rough position data 32a, which is the independent positioning result, to obtain precise position data 32b. Calculate. At this time, the positioning calculation unit 29 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 uses a Kalman filter or the like to obtain the precise position data 32b. calculate.

When the positioning calculation unit 29 receives the calculation initialization command 33 from the calculation control unit 27, it rejects the assumption that the wavenumber integer part is continuous and starts calculating the wavenumber integer part and the baseline length again. . Immediately after receiving the calculation initialization command 33, the positioning calculation unit 29 temporarily waits until it determines the wavenumber integer part of the continuous wave, since it is possible to estimate only the wavenumber fractional part of the continuous wave at the carrier wave phase 8 of the satellite signal 10. positioning accuracy decreases. If the wave number fractional part and the wave number integer part of the carrier wave phase difference cannot be determined, the positioning calculation unit 29 determines that the interferometric positioning calculation has failed. The positioning calculation unit 29 outputs the precise position data 32b as the position information 32 when the precise position data 32b can be calculated, and outputs the approximate position data 32a as the position information 32 only when the precise position data 32b cannot be calculated. do. The positioning calculation unit 29 outputs position information 32 to the calculation control unit 27.

[Communication Department]
The communication unit 21 transmits generated position information 108 (described later) received from the calculation control unit 27 to the distribution server 5. The distribution server 5 generates a correction signal 14 according to the generated position information 108 received from the communication section 21 and outputs it to the communication section 21 . The correction signal 14 that the communication unit 21 receives from the distribution server 5 includes at least the identification number 100 of the positioning satellite 3, the time 102 when the virtual reference station 6 generated the correction signal 14, the pseudorange 7, the carrier phase 8, and the virtual reference station ID 101. include. The communication unit 21 outputs the correction signal 14 received from the distribution server 5 to the calculation control unit 27. The communication unit 21 may fail to receive the correction signal 14 if, for example, there is a radio wave interference or a failure occurs in either the communication unit 21 or the distribution server 5.

[Correction signal DB]
The correction signal DB 25 records the correction signal 14 and processing information 106 (described later in FIG. 3) according to instructions from the calculation control unit 27. The correction signal DB 25 includes at least the identification number of the positioning satellite 3, the time when the virtual reference station 6 generated the correction signal 14, the pseudorange 7, the carrier phase 8, and the virtual reference station ID 101 as the correction signal 14 received from the calculation control unit 27 in the past. recorded. The correction signal DB 25 acquires the correction signal 14 that the calculation control unit 27 received from the distribution server 5 via the communication unit 21 from the calculation control unit 27, and stores the correction signal 14.

FIG. 2 is a data table showing details of the correction signal 14 recorded by the correction signal DB 25. The correction signal DB 25 stores the correction signals 14 in the storage device in the chronological order of the time 102 when the virtual reference station 6 generated the correction signal 14, and at the same time stores the correction signals 14 in the order of the identification IDs 100 of the positioning satellites 3 at least. do. If a correction signal 14 at the same time and from the same positioning satellite as the correction signal 14 received from the arithmetic control unit 27 has already been recorded, the correction signal DB 25 contains the pseudorange 7 and carrier phase of the recorded correction signal 14. 8. Update the virtual reference station ID 101. The correction signal DB 25 determines the data group 103 having the latest time 102 at which the recorded virtual reference station 6 generated the correction signal 14 as the latest correction signal 14 . FIG. 2 shows an example in which correction signals 14 from 07:00:00 to 07:30:00 are stored, and data group 103 with time 102 of "07:30:00" is the latest correction signal 14. corresponds to

FIG. 3 shows the processing information 106 recorded by the correction signal DB 25. The processing information 106 includes at least the identification number 110 of the positioning satellite 3, the carrier phase correction amount 104 of each positioning satellite 3, the virtual reference station ID 107 after change, and the virtual reference station ID 109 before change. The carrier wave phase correction amount 104 is information for correcting the carrier wave phase 8 included in the correction signal 14 that the calculation control unit 27 receives from the communication unit 21, and is calculated by the carrier wave phase correction amount calculation unit 24, and is calculated by the calculation control unit 27. 27 and recorded in the correction signal DB 25. The changed virtual reference station ID 107 is a value to be changed when the calculation control unit 27 changes the virtual reference station ID 101 of the correction signal 14 received from the communication unit 21. The pre-change virtual reference station ID 109 is a value used by the calculation control unit 27 as a comparison value to detect a change in the virtual reference station ID 101 from the correction signal 14 received from the communication unit 21 . The post-change virtual reference station ID 107 and the pre-change virtual reference station ID 109 are determined by the calculation control unit 27 and recorded in the correction signal DB 25.

The correction signal DB 25 is configured such that the stored data 40 (correction signal 14 and processing information 106) can always be referred to by the correction signal prediction unit 22 and the calculation control unit 27. When the correction signal DB 25 cannot secure a sufficient storage area, for example, it records the correction signal 14 only for a predetermined period of time, and when the recording time exceeds a certain period, it executes a process of deleting the oldest record. You may. Further, when the correction signal DB 25 receives the initialization command 34 from the calculation control unit 27, it deletes all records of the recorded correction signal 14 and processing information 106.

[Correction signal prediction unit]
The correction signal prediction unit 22 calculates the correction signal 14 recorded in the correction signal DB 25 and the correction signal received from the calculation control unit 27 based on the stored data 40 of the correction signal DB 25 and the correction signal 14 from the calculation control unit 27. Corrected signal prediction information 35 is calculated from 14. The correction signal prediction unit 22 calculates the pseudo distance 7 and carrier phase 8 described in the correction signal 14 received from the calculation control unit 27 based on the stored data 40 (past correction signal 14) recorded in the correction signal DB 25. A mathematical model for predicting is constructed and calculated as corrected signal prediction information 35. Hereinafter, in this specification, the time written in the correction signal 14 received by the correction signal prediction unit 22 from the calculation control unit 27 will be referred to as “t”.

FIG. 4 shows a mathematical model regarding the pseudorange 7 and the carrier phase 8 that the correction signal prediction unit 22 calculates as the correction signal prediction information 35. FIG. 4(a) is a graph of the mathematical model, in which (b) shows equation 1, (c) shows equation 2, and (d) shows equation 3. In the correction signal prediction information 35, as shown in FIG. It is expressed by a mathematical model calculated using a value of 8. The past five times recorded in the correction signal DB 25 are respectively t ₁ , t ₂ , t ₃ , t ₄ , t ₅ , and the pseudo distance 7 or carrier phase 8 corresponding to the times are y ₁ , y ₂ , y ₃ , y ₄ , y ₅ , these can be expressed as (Equation 1) and (Equation 2), and the estimated value of pseudorange 7 or carrier phase 8 at time t is shown in FIG. 8(d). It can be obtained using (Equation 3).

The correction signal prediction unit 22 constructs a mathematical model for all the positioning satellites 3 described in the correction signal 14 received from the calculation control unit 27 at time t, based on the correction signal DB 25 and the calculation control unit 27, Calculate correction signal prediction information 35. FIG. 5 shows the parameters of the mathematical model that the correction signal prediction unit 22 calculates as the correction signal prediction information 35 based on the correction signal DB 25. The correction signal prediction unit 22 calculates, as correction signal prediction information 35, parameters of a mathematical model that predicts the pseudorange 142 and carrier phase 143 of each positioning satellite 141 at time t. For example, when the pseudorange 142 and carrier phase 143 of a specific positioning satellite 3 are recorded in the correction signal DB 25 at five or more times in the past, the correction signal prediction unit 22 generates correction signal prediction information corresponding to the positioning satellite 3. Calculate 35. The correction signal prediction unit 22 does not calculate the correction signal prediction information 35 if the pseudorange 142 and carrier phase 143 of the specific positioning satellite 3 have not been recorded at five or more times in the past.

The correction signal prediction unit 22 calculates the difference between the correction signal 14 received from the calculation control unit 27 and the predicted value predicted from the correction signal prediction information 35 as a correction signal prediction error 36, as shown in FIG. The correction signal prediction unit 22 may calculate the correction signal prediction information 35 and the correction signal prediction error 36 only when receiving the correction signal 14 from the calculation control unit 27, or may set a control period of 5 seconds or 10 seconds. , the correction signal prediction information 35 and the correction signal prediction error 36 may be calculated for the correction signal 14 most recently received from the calculation control unit 27 in the control period. The correction signal prediction unit 22 outputs correction signal prediction information 35 and correction signal prediction error 36 to the prediction result DB 26.

[Prediction result DB]
The prediction result DB 26 records the correction signal prediction information 35 of the positioning satellite 3 and the correction signal prediction error distribution 163 (see FIG. 7) based on the output of the correction signal prediction unit 22. The prediction result DB 26 records the correction signal prediction information 35 in the format shown in FIG. The prediction result DB 26 calculates a correction signal prediction error distribution 163 that is a probability distribution of the correction signal prediction error 36 by receiving and recording the correction signal prediction error 36 from the correction signal prediction unit 22. As a result, if the vertical axis indicates the probability of occurrence and the horizontal axis indicates the correction signal prediction error 36, a graph as shown in FIG. 7(a) representing the correction signal prediction error distribution 163 can be generated.

The prediction result DB 26 calculates and records the correction signal prediction error distribution 163 for all the positioning satellites 3 for which the correction signal prediction information 35 has been calculated. The prediction result DB 26 is configured such that the correction signal prediction information 35 and the correction signal prediction error distribution 163 can be referred to by the pseudorange continuity detection section 23 and the carrier phase correction amount calculation section 24. For example, if there is a positioning satellite 3 whose correction signal prediction information 35 is not updated for a predetermined period of time or more, the prediction result DB 26 stores the correction signal prediction information 35 associated with the positioning satellite 3 recorded in the prediction result DB 26. And a process of deleting the correction signal prediction error distribution 163 may be executed. Further, when the prediction result DB 26 receives the initialization command 37 from the arithmetic control unit 27, it deletes the correction signal prediction information 35 and correction signal prediction error distribution 163 of all the recorded positioning satellites 3.

[Pseudorange continuity detection unit]
The pseudorange continuity detection section 23 operates only when receiving the correction signal 14 from the calculation control section 27. The pseudorange continuity detection unit 23 uses the correction signal prediction information 35 and the correction signal prediction error distribution 163 based on the prediction result DB 26 and the calculation control unit 27 to calculate the information written in the correction signal 14 received from the calculation control unit 27. The continuity of the pseudo distance 7 is detected. The pseudorange continuity detector 23 notifies the arithmetic controller 27 of the continuity information 38 of the pseudorange 7 written in the correction signal 14 received from the arithmetic controller 27 . The calculation control unit 27 can determine whether the positioning calculation unit 29 needs to be initialized according to the continuity information 38 of the pseudorange 7 written in the correction signal 14 received from the pseudorange continuity detection unit 23. .

FIG. 8 is a flowchart showing the processing of the pseudorange continuity detection unit 23. The flowchart shown in FIG. 8 shows the process performed by the pseudorange continuity detection unit 23 after the pseudorange continuity detection unit 23 receives the correction signal 14 from the calculation control unit 27. First, the pseudorange continuity detection unit 23 checks whether the correction signal prediction information 35 is recorded in the prediction result DB 26 (step S301). If it is not recorded here, the process advances to step S313, and if it is recorded, the pseudorange continuity detection unit 23 calculates S_SUM, which is the total number of positioning satellites 3 described in the correction signal 14 received from the arithmetic control unit 27. is calculated (step S302). Next, the pseudorange continuity detection unit 23 checks whether S_SUM is 5 or more and interferometric positioning is possible (step S303).

In step S303, if S_SUM is 5 or more, the first positioning satellite 3 listed in the correction signal 14 is selected as S, the variable S is set to 1, and the count value N is cleared to zero. (Step S304). In step S303, if S_SUM is 5 or less, the process advances to step S313. Next, the pseudorange continuity detection unit 23 uses the mathematical model of the correction signal prediction information 35 regarding the pseudorange 7 to determine whether the virtual reference station 6 is able to detect the correction signal 14 included in the correction signal 14 received from the calculation control unit 27. The value of the pseudorange 7 regarding the positioning satellite S at the generated time t is predicted (step S305). Next, the pseudorange continuity detection unit 23
A pseudorange prediction error ε1 is calculated, which is the difference between the predicted value of the pseudorange 7 calculated in step 305 and the actual measured value of the pseudorange 7 included in the correction signal 14 received from the calculation control unit 27 (step S306). Further, the pseudorange continuity detection unit 23 calculates a pseudorange prediction error threshold ε1_MAX, which is a threshold for determining whether the pseudorange 7 to the positioning satellite S is accurately predicted in step S305 (step S307). The pseudorange prediction error threshold ε1_MAX is, for example, a value in the 1σ, 2σ, or 3σ interval of the correction signal prediction error distribution 163 recorded in the prediction result DB 26, and the pseudorange prediction error ε1 calculated in step S306 exceeds the threshold. At this time, it is determined that the pseudo distance 7 to the positioning satellite S is not accurately predicted. Note that it is optional which value in the range of 1σ to 3σ is adopted as the threshold value.

In step S308, the pseudorange continuity detection unit 23 determines whether the pseudorange prediction error ε1 is greater than or equal to the pseudorange prediction error threshold ε1_MAX. If it is greater than or equal to ε1_MAX, the count N of satellites for which the continuity of the pseudorange 7 has been lost is incremented, and if it is less than the threshold, the process proceeds to step S311 without performing any specific processing (steps S308, S309). Next, the pseudorange continuity detection unit 23 determines whether all the positioning satellites 3 listed in the correction signal 14 received from the arithmetic control unit 27 as the positioning satellites S have been selected (step S311). If all the positioning satellites 3 have not been selected, the variable S indicating the next positioning satellite 3 is incremented (step S310), and the process returns to step S305. If all the positioning satellites 3 have been selected, that is, if S=S_SUM, it is determined whether the number N of satellites for which the continuity of the pseudorange 7 has been lost is greater than or equal to the positioning satellite number threshold N_MAX (step 312).

In step S312, if the number of positioning satellites is equal to or greater than the threshold, the process proceeds to step S313, and if it is less than the number of positioning satellites, the process proceeds to step S314. The method for determining the positioning satellite number threshold N_MAX is set based on, for example, whether the continuity of the pseudorange 7 is lost in α% or more of the positioning satellites 3 described in the correction signal 14 received from the calculation control unit 27. You may. In that case, the formula for calculating N_MAX is given by (Formula 4) with S_SUM shown in FIG. 7(b) as a variable.

In step S313, the arithmetic control unit 27 is notified as continuity information 38 (see FIG. 1) that continuity has been lost regarding the pseudo distance 7 of the correction signal 14 received from the arithmetic control unit 27. In step S314, the arithmetic control unit 27 is notified as continuity information 38 that the pseudo distance 7 of the correction signal 14 received from the arithmetic control unit 27 is continuous.

[Carrier phase correction amount calculation unit]
The carrier phase correction amount calculation unit 24 operates only when the correction signal 14 is received from the calculation control unit 27. In the correction signal 14 distributed by the distribution server 5, when the virtual reference station 6 is generated again, the carrier wave of the correction signal 14 received by the arithmetic control unit 27 is due to phase observation of the carrier wave phase 8 being stopped for a certain period of time. Phase 8 may include a bias. Based on the prediction result DB 26 and the calculation control unit 27, the carrier phase correction amount calculation unit 24 determines whether a bias is included in the carrier phase 8 described in the correction signal 14 received from the calculation control unit 27, and determines whether the bias is included. If so, a carrier phase correction amount 104, which is a bias correction amount, is calculated.

FIG. 9 is a flowchart showing the processing of the carrier phase correction amount calculation unit 24. First, the carrier phase correction amount calculating section 24 calculates S_SUM, which is the total number of positioning satellites 3 written in the correction signal 14 received from the calculation control section 27, and calculates the total number of positioning satellites 3 written in the correction signal 14. is selected as S (step S321). S_SUM is the same as the value calculated by the pseudorange continuity detection unit 23 in step S302 of FIG. 8. Next, the carrier phase correction amount calculation unit 24 sets a variable S indicating the positioning satellite 3 to 1 (step S322). Next, the carrier phase correction amount calculation unit 24 uses the mathematical model of the correction signal prediction information 35 recorded in the prediction result DB 26 to correct the virtual reference station 6 described in the correction signal 14 received from the calculation control unit 27. The value of carrier phase 8 regarding positioning satellite S at time t when signal 14 is generated is predicted (step S323).

Next, the carrier phase correction amount calculation section 24 calculates a carrier phase prediction error ε2 which is the difference between the calculated predicted value of the carrier phase 8 and the actual measured value of the carrier phase 8 included in the correction signal 14 received from the calculation control section 27. is calculated (step S324), and a carrier phase prediction error threshold ε2_MAX, which is a threshold for determining whether the carrier phase 8 for the positioning satellite S is accurately predicted, is calculated (step S325). The carrier phase prediction error threshold ε2_MAX is, for example, a value in the 1σ, 2σ, or 3σ interval of the correction signal prediction error distribution 163 recorded in the prediction result DB 26, and the carrier phase prediction error ε2 calculated in step S324 exceeds the threshold. In this case, it can be determined that the carrier wave phase 8 for the positioning satellite S is not accurately predicted.

Next, the carrier phase correction amount calculation unit 24 determines whether the carrier phase prediction error ε2 is greater than or equal to the carrier phase prediction error threshold ε2_MAX (step S326). Here, if the carrier phase prediction error ε2 is greater than or equal to ε2_MAX, the integer component of the carrier phase prediction error ε2 is output to the calculation control unit 27 as the carrier phase correction amount 104 of the positioning satellite S (step S327), and if the carrier phase prediction error ε2 is less than ε2_MAX. If the value is less than the threshold, the process proceeds to step S328 without performing any specific processing. In step S328, variable S is incremented.

The carrier phase correction amount calculation unit 24 determines whether all the positioning satellites 3 listed in the correction signal 14 received from the calculation control unit 27 have been selected as the positioning satellites S (step S329). Here, if all of the positioning satellites S have not been selected, the next positioning satellite 3 is selected and the process returns to step S323, and if it has been selected, the process shown in FIG. 9 is ended.

[Calculation control section]
The arithmetic control unit 27 receives the position information from the positioning arithmetic unit 29 by issuing operation commands to the positioning arithmetic unit 29, the communication unit 21, the correction signal prediction unit 22, the pseudorange continuity detection unit 23, and the carrier phase correction amount calculation unit 24. Obtain information 32. The calculation control unit 27 then transmits the acquired position information 32 to an external device. Regarding the external device, the present invention is not particularly limited, and the information can be transmitted to various devices. For example, when the present invention is used in an automatic driving system for agricultural machinery (agricultural machinery), a control module that requires position information 32 of the agricultural machinery corresponds to the external device. Furthermore, various devices such as a monitoring device, a server device, a terminal device, etc. that acquire the position information 32 of agricultural machinery and use it for monitoring, recording, etc. also fall under the category of external devices.

The arithmetic control unit 27 references and edits data recorded in the correction signal DB 25 and the prediction result DB 26. The order in which the calculation control unit 27 issues operation commands to the positioning calculation unit 29, the communication unit 21, the correction signal prediction unit 22, the pseudorange continuity detection unit 23, and the carrier phase correction amount calculation unit 24 and the determination method will be described later. .

The calculation control unit 27 receives the correction signal 14 for the virtual reference station 6 from the distribution server 5 by transmitting the generated position information 108 to the distribution server 5 via the communication unit 21 . The generation position information 108 includes the position at which the distribution server 5 generates the virtual reference station 6, and is recorded in the calculation control unit 27. If the virtual reference station ID 101 of the correction signal 14 received from the communication unit 21 has been changed, the calculation control unit 27 determines that the distribution server 5 has stopped the calculation of the virtual reference station 6 and has generated the virtual reference station 6 again. Then, the arithmetic control unit 27 transmits the correction signal 14 received from the communication unit 21 to the pseudorange continuity detection unit 23, thereby detecting the continuity of the pseudorange 7 described in the correction signal 14 received from the communication unit 21. Check the gender.

When the pseudorange continuity detection unit 23 confirms the continuity of the pseudorange 7 described in the correction signal 14 received from the communication unit 21, the calculation control unit 27 causes the carrier phase correction amount calculation unit 24 to It transmits the correction signal 14 received from the carrier wave phase correction amount 104 and instructs calculation of the carrier phase correction amount 104. Then, the calculation control unit 27 uses the carrier phase correction amount 104 acquired from the carrier wave phase correction amount calculation unit 24 to correct the carrier wave phase 8 described in the correction signal 14 received from the communication unit 21, and also corrects the carrier wave phase 8 described in the correction signal 14 received from the communication unit 21. The ID 101 is changed to the value before the virtual reference station 6 was generated again, and the corrected signal 14 after the change is output to the positioning calculation unit 29 and the corrected signal DB 25. The arithmetic control unit 27 determines the post-change virtual reference station ID 107 and the pre-change virtual reference station ID 109, and records them in the correction signal 14 as processing information 106.

[Entire positioning device]
Hereinafter, with reference to FIGS. 10 to 12, the order in which the arithmetic control section 27 issues operation commands and the determination method thereof will be described. 10 to 12 are flowcharts showing the positioning process of the positioning device 20, and are divided into three diagrams. First, when the positioning device 20 is activated and a positioning operation is started, the arithmetic control unit 27 checks whether the generated position information 108 is recorded (step S201). Here, if the calculation control unit 27 has not recorded the generated position information 108, the process advances to step S227, and if it has recorded the generated position information 108, it transmits the generated position information 108 to the communication unit 21 (step 202). In step S203, the communication unit 21 transmits the generated position information 108 received from the calculation control unit 27 to the distribution server 5, so that the communication unit 21 receives the correction signal 14 corresponding to the generated position information 108 from the distribution server 5. , transmits the received correction signal 14 to the calculation control section 27.

Next, the arithmetic control unit 27 checks whether the correction signal 14 has been received from the distribution server 5 via the communication unit 21 (step S204). If it has been successfully received, the process advances to step S205. If it cannot be received, the process advances to step S234. In step S205, the calculation control unit 27 checks whether the pre-change virtual reference station ID 109 is recorded in the correction signal DB 25 as the processing information 106. If recorded, the process advances to step S206. If not recorded, the process advances to step S212.

In step S206, the calculation control unit 27 checks whether the virtual reference station ID 101 of the correction signal 14 received from the communication unit 21 in step S204 is different from the pre-change virtual reference station ID 109. If they are different, the process advances to step S207; if they are the same, the process advances to step S213. In step S213, the calculation control unit 27 checks whether the changed virtual reference station ID 107 is recorded as the processing information 106 in the correction signal DB 25. If it has been recorded, the process advances to step S221. If not recorded, the process advances to step S223.

In step S207, the calculation control unit 27 outputs the correction signal 14 received from the communication unit 21 in step S204 to the pseudorange continuity detection unit 23. Next, the pseudorange continuity detection unit 23 executes the processes from step S301 to step S314 shown in FIG. reference) is output to the calculation control unit 27 (step S208). After step S208, continuing from FIG. 11, the calculation control unit 27 checks from the continuity information 38 whether the pseudo distance 7 of the correction signal 14 received from the communication unit 21 is continuous (step S209). Here, if the pseudo distance 7 is continuous, the process proceeds to step S210, and if it is not continuous, the process proceeds to step S214.

In step S210, the calculation control unit 27 outputs the correction signal 14 received from the communication unit 21 in step S204 to the carrier phase correction amount calculation unit 24. Next, the carrier phase correction amount calculation unit 24 executes the processes from step S321 to step S329 shown in FIG. It is output to the control unit 27 (step S211). Next, the calculation control unit 27 sets the virtual reference station ID 101 written in the correction signal 14 received from the communication unit 21 in step S204 as the pre-change virtual reference station ID 109, and records it as the processing information 106 of the correction signal DB 25 (step S217).

Next, the arithmetic control unit 27 checks whether the changed virtual reference station ID 107 is recorded in the correction signal DB 25 as the processing information 106 (step S218). If it is recorded, the process proceeds to step S220, and if it is not recorded, the arithmetic control unit 27 sets the changed virtual reference station ID 107 to the value of the pre-changed virtual reference station ID 109, and records it as the processing information 106 of the correction signal DB 25. (Step 219). Next, the arithmetic control unit 27 changes the pre-change virtual reference station ID 109 to the value of the virtual reference station ID 101 written in the correction signal 14 received from the communication unit 21 in step S204, and records it as the processing information 106 of the correction signal DB 25 ( Step S220).

Next, the arithmetic control unit 27 changes the value of the virtual reference station ID 101 written in the correction signal 14 received from the communication unit 21 in step S204 to the value of the changed virtual reference station ID 107 recorded as the processing information 106 of the correction signal DB 25. (Step S221). Next, the arithmetic control unit 27 calculates each of the correction signals 14 described in the correction signal 14 received from the communication unit 21 in step S204 based on the carrier phase correction amount 104 of each positioning satellite 3 recorded as the processing information 106 in the correction signal DB 25. The carrier wave phase 8 of the positioning satellite 3 is corrected (step S222).

If the process proceeds to step S214 in step 209, the calculation control unit 27 initializes the correction signal DB 25 by deleting the correction signal 14 and processing information 106 recorded in the correction signal DB 25 (step S214), and performs calculation control. The prediction result DB 26 is initialized by the unit 27 deleting the correction signal prediction information 35 and the correction signal prediction error distribution 163 recorded in the prediction result DB 26 (step S215). Further, the generation position information S216 recorded by the calculation control unit 27 is initialized (step S216), and the process proceeds to step S223.

In step S223, the calculation control unit 27 transmits the correction signal 14 received from the communication unit 21 to the correction signal prediction unit 22, and instructs the correction signal prediction unit 22 to perform processing. Continuing from FIG. 12, next, the calculation control unit 27 records the correction signal 14 received from the communication unit 21 in the correction signal DB 25 (step S224). Next, the calculation control unit 27 transmits the correction signal 14 received from the communication unit 21 to the positioning calculation unit 29 (step S225), and instructs the positioning calculation unit 29 to perform interferometric positioning (step S226).

In step S234, the calculation control unit 27 checks whether the correction signal 14 is recorded in the correction signal DB 25. If recorded, the calculation control section 27 transmits the correction signal 14 recorded in the correction signal DB 25 to the positioning calculation section 29 (step S235). At this time, the calculation control section 27 may transmit the latest correction signal 14 recorded in the correction signal DB 25 to the positioning calculation section 29. After transmission, the process advances to step S226m. If the correction signal 14 is not recorded in step 234, the process advances to step S227.

In step S227, the calculation control unit 27 instructs the positioning calculation unit 29 to perform independent positioning. Then, the calculation control unit 27 determines whether the positioning calculation unit 29 has succeeded in interferometric positioning (step S228). Here, the positioning calculation unit 29 determines that interferometric positioning has been successful when either the fractional wave number part or the integer wave number part of the carrier phase difference is determined. If the interferometric positioning is successful, the positioning calculation unit 29 calculates precise position data 32b by correcting the independent positioning result with the interferometric positioning result, and outputs it to the calculation control unit 27 as position information 32 (step S229). If the interferometric positioning fails, the positioning calculation unit 29 calculates approximate position data 32a that is the result of independent positioning, and outputs it to the calculation control unit 27 as position information 32 (step S230). After that, the calculation control unit 27 outputs the position information 32 to the external device (step S231).

Finally, the calculation control unit 27 determines whether the generated position information 108 is recorded (step S232). If it is being recorded, the process ends. If not recorded, the process ends after the calculation control unit 27 records the position information 32 output by the positioning calculation unit 29 as the generated position information 108 (step S233).

As explained above, in the positioning device 20 of the present embodiment, when the virtual reference station ID 101 written in the correction signal 14 received by the communication unit 21 from the distribution server 5 is changed, the virtual reference station ID 101 written in the received correction signal 14 is changed. The continuity of the pseudo distance 7 is detected. Then, when the continuity of the pseudorange 7 described in the received correction signal 14 is detected, the positioning device 20 calculates the carrier phase correction amount 104. The positioning device 20 changes the virtual reference station ID 101 written in the received correction signal 14 to the value before the change, corrects the carrier wave phase 8 written in the correction signal 14 based on the carrier wave phase correction amount 104, and performs positioning. Perform calculations. With this configuration, even if the virtual reference station 6 is generated again by the distribution server 5 and the positioning calculation of the positioning device 20 is initialized, the positioning calculation can be performed by detecting the continuity of the satellite signal at the virtual reference station 6. If the re-generated virtual reference station 6 is re-generated at the same position or in the vicinity of the position before generation, the positioning device 20 can continue positioning calculations, which prevents the deterioration of positioning accuracy. It can be prevented.

Next, a second embodiment of the present invention will be described using FIGS. 13 and 14. Here, only the differences from the first embodiment will be explained, and the explanation of the same parts as the first embodiment will be omitted. The second embodiment differs from the first embodiment in that the calculation control unit 27 outputs not only position information 32 but also positioning state information 170 of the positioning calculation unit 29 to an external device (for example, an external terminal). It is. The positioning state information 170 is information indicating whether the position information 32 output from the calculation control unit 27 is rough position data 32a or precise position data 32b.

FIG. 13 is a diagram showing the data structure of the positioning status information 170 output by the positioning calculation unit 29. The positioning status information 170 is synchronized with the time 171 when the positioning information 32 was calculated, and includes information indicating the positioning status of the positioning calculation unit 29, that is, positioning status data 172 and correction signal data 173. The positioning state data 172 is "SINGLE" when the position information 32 is the rough position data 32a, and is "SINGLE" when the position information 32 is the precise position data 32b and the positioning calculation unit 29 determines only the wave number fraction part of the carrier phase difference in interferometric positioning. If the position information 32 is precise position data 32b and the positioning calculation unit 29 has determined the wave number fraction part and the wave number integer part of the carrier phase difference in interferometric positioning, it is written as "FIX". In the correction signal data 173, if the correction signal 14 used by the positioning calculation unit 29 for the positioning calculation is not changed by the calculation control unit 27, “N” indicating No is stored, and the positioning calculation unit 29 is used for the positioning calculation. When the used correction signal 14 is changed by the arithmetic control unit 27, "Y" indicating Yes is stored.

In this way, the positioning status information 170 is output from the calculation control unit 27 together with the position information 32 to an external device (for example, an external terminal). It is possible to determine which of the precise position data 32b it is, and it is also possible to determine whether the correction signal 14 used by the positioning calculation unit 29 for positioning calculations has been changed by the calculation control unit 27.

Hereinafter, with reference to FIG. 14, a flowchart will show a processing procedure in which the arithmetic control unit 27 determines the positioning state information 170 and outputs it to an external device. FIG. 14 is an additional process inserted between steps S231 and S232 shown in the flowchart of FIG. 12, and can be realized by a processor included in the arithmetic control unit 27 executing a computer program. After executing step S230 shown in FIG. 12, the calculation control unit 27 checks whether the positioning calculation unit 29 has output the approximate position data 32a as the position information 32 (step S235). If output, the positioning state data 172 of the positioning state information 170 is set to "SINGLE" (step S236). If the approximate position data 32a is not output in step S235, it is determined whether the positioning calculation unit 29 has determined the wave number integer part of the carrier phase difference as a result of interferometric positioning (step S237). If confirmed here, the positioning status data 172 of the positioning status information 170 is set to "FIX" (step S238), and if not confirmed, the positioning status data 172 of the positioning status information 170 is set to "FLOAT". (step S239), and the process advances to step S240.

In step S240, it is checked whether the changed virtual reference station ID 107 is recorded in the correction signal DB 25. If recorded, the "correction signal data" of the positioning state information 170 is set to "Y" (step S241), and if it is recorded, the "correction signal data" of the positioning state information 170 is set to "N". (Step S242). Next, the calculation control unit 27 outputs the positioning state information 170 to the external device (step 243). Note that the positioning state information 170 is preferably transmitted together with the position information 32, and step S243 and step 231 in FIG. 12 are preferably executed as an integrated process. Then, by proceeding to step S231 in FIG. 12, the processing of the positioning device 20 is continued.

In the second embodiment, such a configuration allows the positioning device 20 to notify the external device of the positioning state of the positioning calculation unit 29. Further, the positioning device 20 can notify an external device that the calculation control unit 27 has changed the correction signal 14 and continued the positioning calculation.

Although the present invention has been described above based on examples, the present invention is not limited to the above-mentioned examples, and various changes can be made without departing from the spirit thereof. For example, in FIG. 1, the positioning device 20 is configured to include a GNSS antenna 28, but the system configuration is such that the positioning device 2 to be sold does not include the GNSS antenna 28 and the purchaser prepares the GNSS antenna 28. Also good.

1 Positioning system 3 Positioning satellite 4 Base station 5 Distribution server 6 Virtual reference station 7 Pseudo range 8 Carrier phase 10 Satellite signal 11 Correction signal 12 Position information 14 Correction signal 18 Correction signal prediction information 20 Positioning device 21 Communication unit 22 Correction signal prediction unit 23 Pseudorange continuity detection unit 24 Carrier phase correction amount calculation unit 25 Correction signal DB
26 Prediction result DB
27 Calculation control unit 28 GNSS antenna 29 Positioning calculation unit 31 Satellite signal 32 Position information 32a Rough position data 32b Precise position data 33 Calculation initialization command 34 Initialization command 35 Correction signal prediction information 36 Correction signal prediction error 37 Initialization command 38 Continuous Gender information 40 Stored data 101 Virtual reference station ID
102 Time 104 Carrier phase correction amount 106 Processing information (recorded by correction signal DB 25) 107 Virtual reference station ID after change
108 Generated position information 109 Virtual reference station ID before change
141 Positioning satellite 142 Pseudorange 143 Carrier phase 163 Correction signal prediction error distribution 170 Positioning state information 171 Time 172 Positioning state data 173 Correction signal data

Claims (15)

a communication unit that communicates with a distribution server that provides a correction signal including a pseudorange, carrier phase, and base station identification information according to position information acquired by the virtual reference station; and an antenna unit that receives satellite signals from a positioning satellite. , a positioning calculation unit that calculates position information based on the satellite signal and the correction signal, and a calculation control unit that outputs the correction signal to the positioning calculation unit, and the calculation control unit calculates identification information of the virtual reference station. A positioning system that initializes positioning calculation in the positioning calculation unit when a change in is detected,
a correction signal prediction unit that calculates correction signal prediction information including a prediction model of at least a pseudorange and a carrier phase that will be received by the communication unit at the current time or in the future from the correction signal received in the past;
a pseudorange continuity detection unit that detects continuity of the correction signal from the correction signal and the pseudorange described in the correction signal prediction information;
The positioning system, wherein the calculation control unit does not change base station identification information of the correction signal received from the communication unit when the pseudorange continuity detection unit detects continuity of the correction signal. . The correction signal prediction unit calculates the difference between the output value of a prediction model of the pseudorange value and carrier phase value of the correction signal, and the pseudorange and carrier phase obtained from the correction signal received from the distribution server. 2. The positioning system according to claim 1, wherein corrected signal prediction information including corrected signal prediction accuracy is calculated from the above. 3. The positioning system according to claim 2, wherein the pseudorange continuity detection unit detects the continuity of the correction signal from the correction signal prediction information. a carrier phase correction amount calculation unit that calculates a carrier phase correction amount that is a correction amount of the carrier phase described in the correction signal based on the correction signal prediction unit;
The positioning system according to claim 1, wherein the carrier wave phase correction amount calculation unit outputs the carrier wave phase correction amount to the calculation control unit. 5. The calculation control unit corrects the correction signal using the carrier phase correction amount when the pseudorange continuity detection unit detects continuity of the correction signal. positioning system. 2. The positioning system according to claim 1, wherein the positioning calculation section outputs positioning state information indicating a processing state of the positioning calculation section to the calculation control section together with the position information. The positioning system according to claim 6, wherein the calculation control unit changes the processing state included in the position information based on outputs from the positioning calculation unit and the pseudorange continuity detection unit. a correction signal database that stores the correction signal received by the communication unit;
8. The positioning system according to claim 7, further comprising a prediction result database that stores the prediction model produced by the correction signal prediction unit. a communication unit that communicates with a distribution server that provides a correction signal including a pseudorange, carrier phase, and base station identification information according to position information acquired by the virtual reference station; and an antenna unit that receives satellite signals from a positioning satellite. , comprising a positioning calculation unit that calculates position information based on the correction signal, and a calculation control unit that outputs the correction signal to the positioning calculation unit, and the calculation control unit detects a change in identification information of the virtual reference station. A positioning method in a positioning system that initializes positioning calculation in the positioning calculation unit when
Calculating correction signal prediction information including a prediction model of at least a pseudorange and carrier phase that will be received by the communication unit at the current time or in the future from the correction signal received in the past;
detecting continuity of the correction signal from the correction signal prediction information;
The calculation control section includes:
Initializing the positioning calculation in the positioning calculation unit when a change in the identification information of the virtual reference station is detected and discontinuity of the correction signal is detected based on the continuity detection of the pseudorange;
Even if a change in the identification information of the virtual reference station is detected, the positioning calculation in the positioning calculation unit is not initialized if the continuity of the correction signal is detected based on the continuity detection of the pseudorange. A positioning method in a positioning system characterized by: The positioning system calculates the difference between the output value of a prediction model of the pseudorange value and carrier phase value of the correction signal, and the pseudorange and carrier phase obtained from the correction signal received from the distribution server. ,
10. The positioning method according to claim 9, further comprising calculating correction signal prediction information including correction signal prediction accuracy. The positioning method according to claim 10, wherein the positioning system detects continuity of the correction signal from the correction signal prediction information. 11. The positioning system calculates a carrier phase correction amount, which is a correction amount of a carrier phase written in the correction signal, based on the correction signal prediction information, and outputs the calculated carrier phase correction amount to the calculation control unit. Positioning method described in. 13. The positioning method according to claim 12, wherein the calculation control unit corrects the correction signal using the carrier phase correction amount when continuity of the correction signal is detected. 14. The positioning method according to claim 13, wherein the positioning calculation section outputs positioning state information indicating a processing state of the positioning calculation section to the calculation control section together with the position information. 15. The positioning method according to claim 14, wherein the calculation control unit changes the processing state included in the position information based on a pseudo-range continuity detection result.

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