Positioning device, positioning method, and positioning program

Abstract

To perform capture of GNSS signals with greater accuracy and more reliably capture a desired number of GNSS signals.SOLUTION: A positioning device 10 comprises a code generation unit 61, a correlator 62, a first determination unit 631, a second determination unit 632, and a tracking target determination unit 633. The code generation unit 61 generates a replica code of a positioning signal. The correlator 62 calculates the correlation value of a received positioning signal with the replica code. The first determination unit 631 determines capture of a received positioning signal for each code by using the correlation value. The second determination unit 632 determines priory capture taking the correlation value as input by using a search engine based on past learning results, for codes not determined as captured by the first determination unit 631. The tracking target determination unit 633 hands over information regarding a positioning signal determined as captured by the first determination unit 631 and a positioning signal determined as captured by the second determination unit 632 to tracking processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for acquiring positioning signals. [Background technology]

[0002] A positioning device and a positioning method are described in Patent Document 1. As in Patent Document 1, the positioning device captures a positioning signal, and then tracks the captured positioning signal to perform positioning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent No. 114236577 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional positioning devices and methods, when the level difference between the GNSS signal (positioning code) and noise is small, problems occur such as not being able to capture the GNSS signal with high accuracy and only a small number of captured GNSS signals.

[0005] Therefore, an object of the present invention is to more accurately capture GNSS signals and more reliably capture a desired number of GNSS signals. [Means for solving the problem]

[0006] The positioning device of the present invention includes a code generation unit, a correlator, a first judgment unit, a second judgment unit, and a tracking target determination unit. The code generation unit generates a replica code of the positioning signal. The correlator calculates a correlation value between the received positioning signal and the replica code. The first judgment unit uses the correlation value to determine capture of the received positioning signal for each code. For codes not determined as captured by the first judgment unit, the second judgment unit uses a search engine based on past learning results to determine capture using the correlation value as an input. The tracking target determination unit passes on information on the positioning signal determined as captured by the first judgment unit and the positioning signal determined as captured by the second judgment unit to the tracking process.

[0007] In this configuration, the correlation value is used to determine capture, and the search engine based on the results of AI learning is used to determine capture. This allows the positioning device to capture positioning signals (GNSS signals) with higher accuracy and more reliably capture the desired number of positioning signals.

[0008] In the positioning device of the present invention, the first determination unit stores a first threshold for determining capture of the CN of the received positioning signal and a second threshold higher than the first threshold. The first determination unit does not determine that a positioning signal whose CN is equal to or greater than the first threshold and less than the second threshold is captured. The first determination unit provides the second determination unit with a correlation value of a positioning signal whose CN is equal to or greater than the first threshold and less than the second threshold.

[0009] In this configuration, the second determination can be performed on a positioning signal that is likely to be erroneously determined in the first determination, thereby enabling the positioning device to further improve the capture accuracy.

[0010] In addition, in the positioning device of the present invention, the determination criterion of the first determination unit is lower than that of a configuration that does not use the second determination unit. In this configuration, it is possible to increase the number of positioning signals that can be captured by the first determination while suppressing a decrease in capture accuracy.

[0011] The positioning device of the present invention further includes a positioning calculation unit that performs tracking and positioning processing using information on the positioning signal that has been determined to be captured. With this configuration, tracking and positioning can be performed more reliably. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a functional block diagram of a capture unit of a positioning device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a functional block diagram of a positioning device according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a flowchart showing an example of a method for capturing a positioning signal according to an embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing another example of a method for capturing a positioning signal according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A positioning technique according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a functional block diagram of a capture unit of a positioning device according to an embodiment of the present invention. Fig. 2 is a functional block diagram of a positioning device according to an embodiment of the present invention.

[0014] (Positioning device 10) As shown in FIG. 2, the positioning device 10 includes an antenna 20, a downconverter 30, an encoder 40, a carrier component removal unit 50, a capture unit 60, and a positioning calculation unit 70. The downconverter 30 is configured with an analog circuit. The encoder 40, the carrier component removal unit 50, the capture unit 60, and the positioning calculation unit 70 are configured with a digital electronic circuit including an IC, and an arithmetic processing unit. In the case of the arithmetic processing unit, the arithmetic processing unit includes, for example, a CPU and a storage unit. The storage unit stores a program that realizes the processing of each of the above units. The arithmetic processing unit realizes the processing of each of the above units by executing this program.

[0015] The antenna 20 receives positioning signals transmitted by a plurality of positioning satellites (GNSS (Global Navigation Satellite Systems) satellites). The positioning signals include a carrier signal of about 1.0 GHz to 1.5 GHz, a code for each positioning satellite, and a navigation message. The code and the navigation message are superimposed on the carrier signal. The antenna 20 outputs the received positioning signals to the downconverter 30.

[0016] The downconverter 30 converts the positioning signal to an intermediate frequency (about several MHz) to generate a positioning signal of the intermediate frequency. The downconverter 30 outputs the positioning signal of the intermediate frequency to the encoder 40.

[0017] The encoder 40 samples the intermediate frequency positioning signal, which is an analog signal, at a predetermined number of bits and converts it into a digital signal. The encoder 40 outputs the digitized intermediate frequency positioning signal to the carrier component removal unit 50.

[0018] The carrier component removal unit 50 multiplies the digitized intermediate frequency positioning signal by a replica signal of the carrier signal to extract a baseband component of the positioning signal. The carrier component removal unit 50 outputs the baseband signal to the acquisition unit 60.

[0019] In summary, the acquisition unit 60 performs correlation processing between the baseband signal and the replica code generated by the positioning device 10, and calculates a correlation value. The acquisition unit 60 uses the correlation value to determine whether or not the positioning signal has been acquired for each code (first determination result). Furthermore, the acquisition unit 60 uses a search engine that has undergone AI learning to input the correlation value and determines whether or not the positioning signal has been acquired (second determination result).

[0020] The acquisition unit 60 determines the positioning signal to be tracked based on the first and second determination results. The acquisition unit 60 outputs acquisition information of the positioning signal determined to be the tracking target to the positioning calculation unit .

[0021] The positioning calculation unit 70 performs a tracking process of the positioning signal that has been determined to have been captured based on the capture information. The positioning calculation unit 70 decodes the navigation message based on the tracking result, and performs positioning based on the navigation message and the tracking result (code pseudorange, ADR, etc.).

[0022] (Capture unit 60) 1, the acquisition unit 60 includes a code generation unit 61, a correlator 62, and an acquisition calculation unit 63. The acquisition calculation unit 63 includes a first determination unit 631, a second determination unit 632, and a tracking target determination unit 633.

[0023] The code generator 61 generates a replica code for each code of the positioning signal, and outputs the replica code to the correlator 62 at a set timing.

[0024] The correlator 62 calculates a correlation value by performing correlation processing between the positioning signal (baseband signal) and the replica code. At this time, the correlator 62 calculates a CN (carrier power to noise power ratio) together with the correlation value. The correlator 62 outputs the correlation value and the CN to the acquisition calculation unit 63.

[0025] (Capture calculation unit 63) The first determination unit 631 stores a threshold value for determining capture based on the correlation value (threshold value for correlation value determination). If the correlation value calculated by the correlator 62 is equal to or greater than the threshold value, the first determination unit 631 determines that the positioning signal on which the correlation value is based has been captured. If the correlation value calculated by the correlator 62 is less than the threshold value, the first determination unit 631 determines that the positioning signal on which the correlation value is based has not been captured.

[0026] The first determination unit 631 outputs acquisition information (such as the code and the code phase at the time of acquisition) for the positioning signal that is determined to have been acquired, to the tracking target determination unit 633. The first determination unit 631 outputs the correlation value of the positioning signal that is determined to have not been acquired, to the second determination unit 632.

[0027] The second judgment unit 632 includes an AI search engine based on a learning model. This learning model is configured as a neural network, and is trained in advance using training data. The training data includes correlation values ​​of low CN signals and noise of various values ​​and patterns. The learning model is configured by repeating learning using these as features to estimate the code that is the source of the features.

[0028] The second determination unit 632 uses an AI search engine to input the correlation value and determine whether or not the positioning signal has been captured. The second determination unit 632 outputs, to the tracking target determination unit 633, capture information for the positioning signal that has been determined to have been captured.

[0029] The tracking target determination unit 633 combines the acquisition information of the positioning signal that the first determination unit 631 determined to have been acquired (acquisition information based on the first determination) and the acquisition information of the positioning signal that the second determination unit 632 determined to have been acquired (acquisition information based on the second determination), and outputs them to the positioning calculation unit 70.

[0030] In this way, the positioning device 10 captures the positioning signal by using both the capture of the positioning signal by the correlation value and the capture of the positioning signal by the AI ​​search engine. At this time, the positioning device 10 can confirm the capture of the positioning signal that could not be captured due to a low correlation value by the AI ​​search engine. Therefore, the positioning device 10 can capture the positioning signal (GNSS signal) with higher accuracy and can reliably capture more positioning signals that can be used for positioning.

[0031] (Method of capturing positioning signals) In the above description, the processes executed by the positioning device are realized by a plurality of functional units, but the following program may be executed by a processor.

[0032] 3 is a flowchart showing an example of a method for capturing a positioning signal according to an embodiment of the present invention. Note that the specific contents of each process have been described above, and detailed description will be omitted except for necessary points.

[0033] The arithmetic processing device calculates a correlation value between the received positioning signal and the replica code (S11). The arithmetic processing device determines whether the positioning signal has been captured by a first determination method using the correlation value (S12).

[0034] If there is a positioning signal that is determined to have been captured by the first determination method (S12: YES), the calculation processing device passes the capture information of this positioning signal on to the tracking process (S13).

[0035] The calculation processing device inputs the correlation value of the positioning signal that could not be determined as having been captured by the first determination method to the AI ​​search engine (S12: NO, S14).

[0036] The arithmetic processing device determines whether the positioning signal has been captured using a second determination method using an AI search engine (S15). If the arithmetic processing device determines that the positioning signal has been captured using the second determination method (S15: YES), the arithmetic processing device passes the capture information of the positioning signal to the tracking process (S13).

[0037] If the first and second determination methods fail to confirm capture of the positioning signals, the processor repeats the above process, for example, while accumulating correlation values, so that a desired number of positioning signals to be used for positioning can be captured.

[0038] (Another method for capturing positioning signals) Fig. 4 is a flowchart showing another example of the method for capturing a positioning signal according to the embodiment of the present invention. Note that in the flow of Fig. 4, the same parts as those in the flow of Fig. 3 will not be described.

[0039] The arithmetic processing device stores a first threshold value for capture determination used in the first determination method. In the first determination method, the arithmetic processing device compares the CN of the positioning signal determined to be captured based on the correlation value with the first threshold value. The arithmetic processing device determines that the positioning signal with a CN equal to or greater than the first threshold value has been captured (S12A: YES). The arithmetic processing device determines that the positioning signal with a CN less than the first threshold value has not been captured (S12: NO).

[0040] The arithmetic processing device stores a second threshold value higher than the first threshold value. The arithmetic processing device compares the CN of the positioning signal whose CN is equal to or greater than the first threshold value with the second threshold value. If the CN is equal to or greater than the second threshold value, the arithmetic processing device determines that the positioning signal has been captured (S21: YES) and proceeds to tracking processing (S13).

[0041] If CN is less than the second threshold, the calculation processing device determines whether or not the positioning signal has been captured using the second determination method (S21: NO).

[0042] With this configuration, the positioning device can determine whether or not the positioning signal is captured using the CN, not just the correlation value, and therefore the positioning device can capture the positioning signal with higher accuracy.

[0043] Furthermore, in this configuration, even if the positioning device determines that the positioning signal with a not sufficiently high CN has been captured based on the correlation value, the positioning device performs the capture determination again using the AI ​​search engine. This allows the positioning device to capture the positioning signal with higher accuracy.

[0044] In this case, the first threshold is set lower than the threshold for judging capture using a conventional CN without using an AI search engine. This allows the positioning device to lower the criterion for judging capture using a CN, and thus capture more positioning signals.

[0045] The positioning device can further suppress the deterioration of the reliability of the capture determination by combining the determination based on the second threshold (for example, a value equal to or slightly lower than the CN threshold for conventional capture determination) with the determination based on the AI ​​search engine. Therefore, the positioning device can capture the positioning signal with higher accuracy while capturing more divergent signals.

[0046] <1> a code generating unit for generating a replica code of the positioning signal; a correlator for calculating a correlation value between the received positioning signal and a replica code; a first determination unit that determines capture of the received positioning signal for each code using the correlation value; a second determination unit that uses a search engine based on past learning results to determine the capture of a code that has not been determined as the capture by the first determination unit, using the correlation value as an input; A positioning device comprising: a tracking target determination unit that transfers information on a positioning signal determined to have been captured by the first determination unit and information on a positioning signal determined to have been captured by the second determination unit to a tracking process.

[0047] <2> <1> A positioning device comprising: The first determination unit is A first threshold value for determining whether or not the CN of the received positioning signal is captured and a second threshold value higher than the first threshold value are stored; The CN does not determine a positioning signal that is equal to or greater than the first threshold and less than the second threshold as the acquisition, The CN provides the second determination unit with a correlation value of the positioning signal that is equal to or greater than the first threshold and less than the second threshold.

[0048] <3> <1> or <2> A positioning device comprising: A positioning device, wherein the determination criterion of the first determination unit is lower than that of a configuration that does not use the second determination unit.

[0049] <4> <1> ~ <3> Any one of the positioning devices, A positioning device comprising a positioning calculation unit that performs tracking and positioning processing using information on the positioning signal determined to be captured.

[0050] <5> Generate a replica code of the positioning signal; Calculating a correlation value between the received positioning signal and the replica code; making a first determination of acquisition of the received positioning signal on a code-by-code basis using the correlation values; For the code that has not been determined as the capture in the first determination, a second determination of the capture is made using a search engine based on past learning results and the correlation value as an input; The positioning method includes carrying over information of the positioning signal determined to have been captured in the first determination and information of the positioning signal determined to have been captured in the second determination to a tracking process.

[0051] <6> Generate a replica code of the positioning signal; Calculating a correlation value between the received positioning signal and the replica code; making a first determination of acquisition of the received positioning signal on a code-by-code basis using the correlation values; For the code that has not been determined as the capture in the first determination, a second determination of the capture is made using a search engine based on past learning results and the correlation value as an input; A positioning program that causes a calculation processing device to execute a process of transferring information on the positioning signal determined to have been captured in the first determination and information on the positioning signal determined to have been captured in the second determination to a tracking process. [Explanation of symbols]

[0052] 10: Positioning device 20: Antenna 30: Down converter 40: Encoder 50: Carrier component removal section 60: Capture section 61: Code generation section 62: Correlator 63: Acquisition calculation section 70: Positioning calculation unit 631:First judgment part 632:Second judgment part 633: Tracking target determination unit

Claims

1. a code generating unit for generating a replica code of the positioning signal; a correlator for calculating a correlation value between the received positioning signal and a replica code; a first determination unit that determines capture of the received positioning signal for each code by using the correlation value; a second determination unit that uses a search engine based on past learning results to determine the capture of a code that has not been determined as the capture by the first determination unit, and inputs the correlation value; a tracking target determination unit that transfers information on the positioning signal determined to be captured by the first determination unit and the positioning signal determined to be captured by the second determination unit to a tracking process; A positioning device comprising:

2. The positioning device according to claim 1 , The first determination unit is A first threshold value for determining whether or not the CN of the received positioning signal has been captured and a second threshold value higher than the first threshold value are stored; The CN does not determine a positioning signal that is equal to or greater than the first threshold and less than the second threshold as the acquisition; the CN provides the second determination unit with a correlation value of the positioning signal that is equal to or greater than the first threshold and less than the second threshold; Positioning device.

3. The positioning device according to claim 1 , The judgment criterion of the first judgment unit is lower than that of a configuration not using the second judgment unit. Positioning device.

4. The positioning device according to claim 1 , a positioning calculation unit that performs tracking and positioning processing using information of the positioning signal determined to be acquired; Positioning device.

5. Generate a replica code of the positioning signal; Calculating a correlation value between the received positioning signal and the replica code; making a first determination of acquisition of the received positioning signal on a code-by-code basis using the correlation values; performing a second determination of the capture for the code that has not been determined as the capture in the first determination, using a search engine based on past learning results and inputting the correlation value; information on the positioning signal determined to have been captured in the first determination and information on the positioning signal determined to have been captured in the second determination are passed on to a tracking process; Positioning method.

6. Generate a replica code of the positioning signal; Calculating a correlation value between the received positioning signal and the replica code; making a first determination of acquisition of the received positioning signal on a code-by-code basis using the correlation values; performing a second determination of the capture for the code that has not been determined as the capture in the first determination, using a search engine based on past learning results and inputting the correlation value; information on the positioning signal determined to have been captured in the first determination and information on the positioning signal determined to have been captured in the second determination are passed on to a tracking process; A positioning program that causes a processor to execute the process.

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