Electronic apparatus

Abstract

To provide an electronic apparatus capable of accurately determining a positioning environment.SOLUTION: An electronic apparatus includes: an antenna for receiving a plurality of satellite signals to be transmitted from a plurality of satellites; a positioning section for performing first to the N-th positioning at mutually different timing based on the satellite signals; and a determination section for determining a positioning environment being the environment to perform the first to the N-th positioning. The positioning section performs: calculating the i-th positioning residual, with respect to each one of integers i equal to or greater than one and equal to or smaller than N, based on a distance between the i-th position of a reception point obtained by the i-th positioning and a position of each one of the satellites used in the i-th positioning and also based on a distance of propagation of each one of the satellite signals used in the i-th positioning; and calculating the (i-1)th distance being the distance from the (i-1)th position to the i-th position with respect to each one of integers i equal to or greater than 2 and equal to or smaller than N. The determination section determines the positioning environment based on the first to the N-th positioning residuals and the first to the (N-1)-th distances.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] Patent document 1 describes a mobile phone that receives RF signals including GPS satellite signals transmitted from GPS satellites, determines the positioning environment as needed in accordance with positioning environment determination conditions that use the electric field strength of the received signals, sets which of multiple search modes to assign to the satellite to be captured as needed in accordance with the positioning environment, and captures the satellite to be captured in accordance with the assigned search mode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-103021 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the positioning environment is poor, the received signal contains not only GPS satellite signals but also noise such as signals reflected by buildings, etc. However, the mobile phone described in Patent Document 1 determines that the positioning environment is good if the electric field strength is high even if the received signal contains noise, making it difficult to accurately determine the positioning environment. [Means for solving the problem]

[0005] One aspect of the electronic device according to the present invention is N is an integer equal to or greater than 2, an antenna for receiving a plurality of satellite signals transmitted from a plurality of satellites; a positioning unit that performs first to Nth positioning at different timings based on the plurality of satellite signals; a determination unit that determines a positioning environment in which the first to Nth positioning operations are performed, The positioning unit For each integer i between 1 and N, calculate an i-th positioning residual based on the distance between the i-th position of the reception point obtained by the i-th positioning and the positions of each of the plurality of satellites used in the i-th positioning and the propagation distance of each of the plurality of satellite signals used in the i-th positioning; For each integer i between 2 and N, calculate an (i-1)th distance, which is the distance from the (i-1)th position to the i-th position; The determination unit The positioning environment is determined based on the first to N-th positioning residuals and the first to N-1th distances. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an electronic device according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of a navigation message in GPS. [Figure 3] FIG. 4 is a diagram showing an example of waveforms of an index, an enable signal, and a timing signal. [Figure 4] FIG. 4 is a flowchart showing an example of a procedure for determining a positioning environment by a positioning unit and a determining unit in the first embodiment. [Figure 5] FIG. 10 is a diagram showing the evaluation results of the indexes. [Figure 6] FIG. 10 is a diagram showing the evaluation results of the indexes. [Figure 7] FIG. 10 is a diagram showing an example of the configuration of an electronic device according to a second embodiment. [Figure 8] FIG. 11 is a flowchart showing an example of a procedure for determining a positioning environment by a positioning unit and a determining unit in the second embodiment. [Figure 9] FIG. 10 is a diagram showing a configuration example of an electronic device according to a modified example. [Figure 10] FIG. 10 is a diagram showing a configuration example of an electronic device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0007] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0008] 1. First embodiment 1-1.Configuration of electronic devices 1 is a diagram showing an example of the configuration of an electronic device 1 according to a first embodiment. As will be described in detail below, the electronic device 1 is a clock signal generating device that receives satellite signals transmitted from a plurality of satellites 2 and generates a highly accurate clock signal CK. As shown in FIG. 1, the electronic device 1 according to the first embodiment includes a GNSS receiving terminal 10 and a measurement processing terminal 20.

[0009] The GNSS receiver terminal 10 includes a positioning unit 11, an output unit 12, and a determination unit 13. The GNSS receiver terminal 10 also includes an antenna 30. However, the GNSS receiver terminal 10 may be configured such that some of these components are omitted or modified, or other elements are added.

[0010] The antenna 30 is an antenna that receives various radio waves including satellite signals transmitted from each of the multiple satellites 2, and is connected to the positioning unit 11. The positioning unit 11 receives multiple satellite signals transmitted from the multiple satellites 2 via the antenna 30, and performs positioning based on the received satellite signals.

[0011] Satellite 2 is an artificial satellite that orbits the Earth in a predetermined orbit and constitutes part of the GNSS. GNSS is an abbreviation for Global Navigation Satellite System. Examples of GNSS include GPS, QZSS, EGNOS, GLONASS, GALILEO, and BeiDou. GPS is an abbreviation for Global Positioning System. QZSS is an abbreviation for Quasi Zenith Satellite System. EGNOS is an abbreviation for European Geostationary Navigation Overlay Service. GLONASS is an abbreviation for Global Navigation Satellite System. The following description will be given taking as an example a case where the satellite system to which satellite 2 belongs is GPS.

[0012] Satellites 2 transmit satellite signals to the Earth, which are radio waves with navigation messages superimposed on them. GPS uses approximately 30 satellites 2, and to identify which satellite 2 transmitted the satellite signal, each satellite 2 superimposes a unique pattern called a C / A code onto the satellite signal. C / A stands for Coarse / Acquisition Code. Each chip of the C / A code is either +1 or -1, and it appears as a random pattern, repeating periodically, for example, every 1 ms. Therefore, the positioning unit 11 can detect the C / A code superimposed on the satellite signal by correlating the satellite signal with the pattern of each C / A code.

[0013] The satellite signals transmitted by each satellite 2 contain orbital information indicating the position of each satellite 2 in its orbit. Each satellite 2 is also equipped with an atomic clock, and the satellite signals contain extremely accurate time information kept by the atomic clock. Therefore, the positioning unit 11 receives satellite signals from four or more satellites 2 and performs positioning calculations using the orbital information and time information contained in each satellite signal, thereby obtaining accurate information on the position and time of the antenna 30, which is the receiving point. Specifically, the positioning unit 11 simply formulates a four-dimensional equation with the three-dimensional position (x, y, z) of the receiving point and time t as four variables, and finds the solution to that equation.

[0014] Additionally, using the orbital information contained in each satellite signal, information on the difference between the time on each satellite 2 and the time at the reception point can be obtained. The slight time error of the atomic clock on each satellite 2 is measured by a ground control segment, and the satellite signal also contains a time correction parameter for correcting this time error; by correcting the time at the reception point using this time correction parameter, extremely accurate time information can be obtained.

[0015] Fig. 2 is a diagram showing the structure of a navigation message in GPS. As shown in Fig. 2, a navigation message in GPS is structured as data with a main frame as one unit. The main frame is divided into five subframes, the first to fifth subframes. The time required for transmitting data for one subframe from each satellite 2 is, for example, six seconds, and the time required for transmitting data for one main frame is 30 seconds.

[0016] The data included in each of the five subframes is divided into words 1 to 10, with each word consisting of, for example, 30 bits. In each subframe, the first word is a TLM word and the second word is a HOW word.

[0017] The HOW word contains time information called TOW or Z-count. TOW is an abbreviation for Time Of Week. Z-count data is displayed in seconds starting from midnight every Sunday and returns to 0 at midnight the following Sunday. In other words, Z-count data is information displayed in seconds for each week from the beginning of the week.

[0018] Returning to the explanation of Fig. 1, the positioning unit 11 generates various information such as position information and time information of the positioning results, and the propagation distance of the satellite signals transmitted from each satellite 2 until they reach the electronic device 1, and generates an index IND for evaluating the positioning environment based on the various information. The positioning unit 11 then outputs the generated index IND to the determination unit 13. The positioning unit 11 also generates a timing signal PPS synchronized with the time of one of the multiple satellites 2 based on the position and time of the reception point obtained by positioning, and outputs this to the output unit 12. PPS is an abbreviation for Pulse Per Second. The timing signal PPS is a pulse signal that is completely synchronized with UTC (Coordinated Universal Time) and includes one pulse per second.

[0019] In this embodiment, the positioning unit 11 performs first to Nth positioning at different timings based on a plurality of satellite signals transmitted from a plurality of satellites 2, and calculates an index IND based on the first to Nth positioning results. Specifically, the positioning unit 11 calculates the ith position PA of the reception point obtained by the ith positioning for each integer i between 1 and N. i and the position of each of the plurality of satellites 2 used in the i-th positioning and the propagation distance of each of the plurality of satellite signals used in the i-th positioning. i where N is an integer of 2 or greater.

[0020] Here, the M satellites 2 used for the ith positioning are the first to M satellites 2-1 to 2-M, and the M satellite signals used for the ith positioning are the first to M satellite signals transmitted from the first to M satellites 2-1 to 2-M, respectively. For each integer j between 1 and M, the ith position PA of the reception point is calculated. i and the position of the jth satellite 2-j, PB jThe difference between the distance and the distance traveled by the jth satellite signal is called the jth residual Δd i Then, the i-th positioning residual Δmd i are the 1st to Mth residuals Δd1 to Δd M The standard deviation of the position PB of the jth satellite 2-j may be j is calculated by a known method using the orbital information included in the j-th satellite signal. The distance traveled by the j-th satellite signal is calculated by subtracting the bias, clock error, ionospheric delay, and tropospheric delay from the observed pseudorange. The observed pseudorange, bias, clock error, ionospheric delay, and tropospheric delay are calculated by a known method using the orbital information and model included in the j-th satellite signal.

[0021] Furthermore, the positioning unit 11 calculates the (i-1)th position PA of the reception point for each integer i between 2 and N. i-1 From the i-th position PA i The i-1th distance D is the distance to i-1 Then, the positioning unit 11 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 An index IND for evaluating the positioning environment in which the first to Nth positioning are performed based on the above. 1,N Calculate.

[0022] The determination unit 13 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 In this embodiment, the determining unit 13 determines the positioning environment based on the index IND calculated by the positioning unit 11. 1,N Specifically, the determining unit 13 determines the positioning environment at the time of the first to Nth positioning based on the index IND 1,N is equal to or less than a predetermined threshold value TH set by the control unit 22 of the measurement processing terminal 20. That is, the determination unit 13 determines whether the index IND 1,N is compared with the threshold TH, and the index IND 1,N is equal to or less than the threshold value TH, the determination unit 13 determines that the positioning environment at the time of the first to Nth positioning is good, and outputs a high level enable signal EN.1,N If the threshold value TH is greater than the threshold value TH, it is determined that the positioning environment at the time of the first to Nth positioning is not good, and a low-level enable signal EN is output. Note that the threshold value TH may be variably set from outside the electronic device 1.

[0023] In this embodiment, the determination unit 13 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 For example, the determining unit 13 determines the positioning environment based on the accumulated values ​​of the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The positioning environment may be determined based on the sum of the accumulated values ​​of the index IND and the index IND as shown in equation (1). 1,N are the 1st to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 It may be the sum of the accumulated values ​​of

[0024]

number

[0025] After completing the (N+1)th positioning, the positioning unit 11 performs the same processing on the second to (N+1)th positioning as on the first to Nth positioning, and calculates an index IND for evaluating the positioning environment at the time of the second to (N+1)th positioning. 2,N+1 The positioning unit 11 performs the same processing as that performed on the first to Nth positionings for each of the positionings after the (N+2)th positioning to calculate an index IND for evaluating the positioning environment of the kth to (k+N-1)th positioning values. k,k+N-1 That is, the positioning unit 11 calculates the index IND each time the Nth positioning and subsequent positioning is completed, and the determination unit 13 updates the enable signal EN to high level or low level each time the index IND is updated.

[0026] The output unit 12 outputs a timing signal PPSO to the time measurement unit 21 of the measurement processing terminal 20 in accordance with the determination result of the positioning environment determined by the determination unit 13. Specifically, when the determination unit 13 determines that the positioning environment is good, i.e., when the enable signal EN is at a high level, the output unit 12 outputs the timing signal PPS output from the positioning unit 11 as the timing signal PPSO. That is, when the index IND calculated by the positioning unit 11 is equal to or less than the threshold value TH, the output unit 12 outputs the timing signal PPS to the time measurement unit 21 as the timing signal PPSO. On the other hand, when the determination unit 13 determines that the positioning environment is not good, i.e., when the enable signal EN is at a low level, the output unit 12 does not output the timing signal PPS output from the positioning unit 11 as the timing signal PPSO, but instead outputs, for example, a timing signal PPSO fixed at a low level. That is, when the index IND is greater than the threshold value TH, the output unit 12 does not output the timing signal PPS to the time measurement unit 21 as the timing signal PPSO.

[0027] Therefore, if the positioning environment is not good, the accuracy of the timing signal PPS output from the positioning unit 11 will deteriorate, or the output of the timing signal PPS from the positioning unit 11 will stop, but in such a case, the output unit 12 will not output the timing signal PPS as the timing signal PPSO. In other words, the output unit 12 selects only the timing signal PPS that is highly accurate when the positioning environment is good, and outputs it as the timing signal PPSO.

[0028] 3 is a diagram showing an example of the waveforms of the index IND, the enable signal EN, and the timing signals PPS and PPSO. As shown in FIG. 3, during a period in which the index IND is equal to or less than a threshold value TH, the enable signal EN is at a high level, and the timing signal PPS is output as the timing signal PPSO. On the other hand, during a period in which the index IND is greater than the threshold value TH, the enable signal EN is at a low level, and the timing signal PPSO fixed at a low level is output.

[0029] Measurement processing terminal 20 includes a time measurement unit 21 and a control unit 22. However, measurement processing terminal 20 may have a configuration in which some of these components are omitted or changed, or other elements are added.

[0030] The control unit 22 transmits various control commands CMD to the positioning unit 11 of the GNSS receiving terminal 10 to control the operation of the positioning unit 11. The control unit 22 also sets a threshold value TH for the determination unit 13 of the GNSS receiving terminal 10.

[0031] The time measurement unit 21 measures time based on the timing signal PPSO output from the output unit 12 of the GNSS receiving terminal 10. In this embodiment, the time measurement unit 21 includes an atomic oscillator 211.

[0032] The atomic oscillator 211 is an oscillator capable of outputting a clock signal with high frequency accuracy that utilizes atomic energy transitions, and atomic oscillators that use, for example, rubidium atoms or cesium atoms are widely known.

[0033] When the output unit 12 of the GNSS receiving terminal 10 outputs the timing signal PPS as the timing signal PPSO, the atomic oscillator 211 generates an accurate clock signal CK synchronized with the timing signal PPSO. On the other hand, when the output unit 12 outputs the timing signal PPSO that is fixed to, for example, a low level, the atomic oscillator 211 performs free-running oscillation and outputs the clock signal CK with high frequency accuracy. The electronic device 1 may output the clock signal CK output by the atomic oscillator 211 to the outside.

[0034] The electronic device 1 of this embodiment may have a configuration in which some of the components shown in FIG. 1 are omitted or changed, or other elements are added.

[0035] 1-2. Positioning environment determination process 4 is a flowchart showing an example of the procedure of the process of determining the positioning environment by the positioning unit 11 and the determination unit 13. As shown in FIG. 4, first, in step S10, the integer i is set to 1, and in step S20, the positioning unit 11 starts the ith positioning. When the ith positioning is completed in step S30, the integer j is set to 1 in step S40, and in step S50, the positioning unit 11 determines the ith position PA of the reception point obtained by the ith positioning. i and the position PB of the jth satellite 2-j used in the ith positioning j and the j-th residual Δd, which is the difference between the distance to the j-th satellite and the distance traveled by the j-th satellite signal transmitted from the j-th satellite 2-j. j Here, the satellite 2-j is one of the M satellites 2-1 to 2-M used for the i-th positioning.

[0036] Then, in step S60, the integer j is incremented by 1 in step S70 until the integer j matches the integer M, and in step S50, the positioning unit 11 calculates the j-th residual Δd j Calculate.

[0037] When the integer j matches the integer M in step S60, the positioning unit 11 then calculates the i-th positioning residual Δmd i The first to Mth residuals Δd1 to Δd M Calculate the standard deviation of

[0038] Next, if the integer i is 2 or more in step S90, the positioning unit 11 determines the (i-1)th position PA i-1 and the i-th position PA i The distance between the i-1th point and the i-1 If the integer i is 1 in step S90, the positioning unit 11 does not perform the process of step S100.

[0039] Next, if the integer i is equal to or greater than the integer N in step S110, the positioning unit 11 calculates the index IND i-N+1,i The positioning residuals Δmd from the i-N+1th to the i-th i-N+1 ~Δmd i and the distance D between the i-N+1th and i-1thi-N+1 ~D i-1 For example, if the integer i is equal to the integer N in step S110, the positioning unit 11 calculates the sum of the index IND 1,N As a result, the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The sum of the accumulated values ​​is calculated.

[0040] Next, in step S130, the determination unit 13 determines the index IND i-N+1,i is compared with the threshold TH, and the index IND i-N+1,i is equal to or less than the threshold value TH, the decision unit 13 outputs a high level enable signal EN, which causes the output unit 12 to output the timing signal PPS as the timing signal PPSO. i-N+1,i If PPSO is greater than the threshold value TH, the decision unit 13 outputs a low-level enable signal EN, which causes the output unit 12 to output, for example, a timing signal PPSO fixed at a low level.

[0041] If the integer i is less than the integer N in step S110, the positioning unit 11 does not perform the process of step S120. If the measurement is not finished in step S160, the integer i is incremented by 1 in step S170, and the positioning unit 11 and the determination unit 13 perform the processes from step S20 onwards again.

[0042] 1-3.Evaluation results of index accuracy The inventors of the present application performed positioning by fixing electronic device 1 at a known position in both a multipath environment and an open-sky environment, and evaluated the accuracy of index IND through simulation by acquiring a time series of the positions of the reception points obtained by positioning. The multipath environment is an example of an unfavorable positioning environment, and the open-sky environment is an example of a favorable positioning environment.

[0043] Graphs of the evaluation results of the index IND are shown in Figures 5 and 6. In Figures 5 and 6, the horizontal axis represents time, and the vertical axis represents distance (unit: m). In Figures 5 and 6, G1 is a time series of the index IND, G2 is a time series of the difference between the position of the reception point obtained by positioning and the true position, i.e., the positioning error, and G3 is a time series of the standard deviation of the positions of the reception point obtained by positioning. The true position is the position where the electronic device 1 is fixed.

[0044] As shown in Figure 5, in a multipath environment, the time series G1 of the index IND varies roughly within a range of 20m to 60m, while the time series G2 of the positioning error varies roughly within a range of 10m to 40m. In particular, after a certain amount of time has passed since the start of positioning, the difference between the time series G1 of the index IND and the time series G2 of the positioning error becomes smaller. On the other hand, the time series G3 of the standard deviation of the position of the reception point varies roughly within a range of 0m to 10m, and the difference with the time series G2 of the positioning error is large.

[0045] Furthermore, as shown in Figure 6, in an open-sky environment, the time series G1 of the index IND varies roughly within a range of 5m to 25m, while the time series G2 of the positioning error varies roughly within a range of 5m to 20m. In particular, the difference between the time series G1 of the index IND and the time series G2 of the positioning error is small immediately after the start of positioning. On the other hand, the time series G3 of the standard deviation of the position of the reception point varies roughly within a range of 0m to 5m, and the difference with the time series G2 of the positioning error is large.

[0046] As shown in Figures 5 and 6, the more the positioning environment deteriorates, the larger the positioning error becomes, but the standard deviation of the reception point position does not change much even when the positioning environment changes, and the difference with the positioning error is also large, so it is not suitable as an index for evaluating the positioning environment.In contrast, the index IND increases or decreases significantly in response to changes in the positioning environment, and the difference with the positioning error is small, so it can be said to be a highly accurate index for evaluating the positioning environment.

[0047] 1-4.Effects As described above, in the electronic device 1 of the first embodiment, the first to Nth positioning residuals Δmd1 to Δmd Nand the first to (N-1)th distances D1 to D2 indicating the distance the receiving point moved at each positioning. N-1 The positioning environment at the time of the N positioning measurements is determined based on the first to Nth positioning residuals Δmd1 to Δmd N Each of the first to Nth positions PA1 to PA2 of the reception points obtained by each positioning is N The error is reflected in the 1st to (N-1th) distances D1 to D N-1 Each of the signals indicates the first to Nth positions PA1 to PA2 of the reception points obtained by each positioning when the position of the electronic device 1 is fixed. N Therefore, the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 tends to increase due to deterioration in positioning accuracy caused by the influence of multipath and attenuation of received satellite signals. Therefore, according to the electronic device 1 of the first embodiment, the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 In particular, according to the electronic device 1 of the first embodiment, the field strength of the received satellite signal or the number of visible satellites is not used as an index for determining the positioning environment, so that the positioning environment can be determined accurately even in cases where, for example, the field strength of the received satellite signal is high but the positioning accuracy deteriorates due to the influence of multipath.

[0048] In particular, in the electronic device 1 of the first embodiment, the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The sum of the cumulative values ​​of IND 1,N The positioning environment is determined as follows. The first to Nth positioning residuals Δmd1 to Δmd N The average value of the first to Nth positions PA1 to PA2 of the reception points obtained by N times of positioning is N The average error of the 1st to N-1th distances D1 to D N-1 The cumulative value of the first to Nth positions PA1 to PA2 of the reception points obtained by N times of positioning when the position of the electronic device 1 is fixed is N Therefore, the index IND1,N , the first to Nth positions of the receiving points PA1 to PA N Therefore, according to the electronic device 1 of the first embodiment, the index IND 1,N By comparing the value with the threshold value TH, the positioning environment can be determined with high accuracy.

[0049] Furthermore, according to the electronic device 1 of the first embodiment, the index IND 1,N is a numerical value of the dimension of distance, just like the positioning error, so the index IND 1,N is suitable as an index for directly evaluating the positioning environment, and for example, the user can easily set the threshold value TH in units of distance.

[0050] Furthermore, in the electronic device 1 of the first embodiment, when it is determined that the positioning environment is good, an accurate timing signal PPS synchronized with the time of the satellite 2 is output to the time measurement unit 21, and when it is determined that the positioning environment is not good, no timing signal PPS is output. Therefore, according to the electronic device 1 of the first embodiment, it is possible to accurately measure time based on the accurate timing signal PPS obtained when the positioning environment is good.

[0051] 2. Second embodiment Hereinafter, for the electronic device 1 of the second embodiment, the same components as those of the first embodiment will be given the same reference numerals, and explanations of the same components as those of the first embodiment will be omitted or simplified, with differences from the first embodiment being mainly described.

[0052] In the first embodiment, when the position of the electronic device 1 is fixed, the index IND is effective as an index for evaluating the positioning environment, but when the electronic device 1 moves, the index IND reflects not only the positioning error but also the distance traveled by the electronic device 1, reducing its effectiveness. Therefore, in the electronic device 1 of the second embodiment, the GNSS receiving terminal 10 calculates the index INDX from which the influence of the distance traveled by the electronic device 1 is eliminated.

[0053] 7 is a diagram showing an example of the configuration of the electronic device 1 of the second embodiment. As shown in FIG. 7, the electronic device 1 of the second embodiment includes a GNSS receiving terminal 10, a measurement processing terminal 20, an acceleration sensor 40, and an angular velocity sensor 50.

[0054] The acceleration sensor 40 detects acceleration in the directions of the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are three axes that are mutually orthogonal and preset for the electronic device 1. The acceleration sensor 40 can detect acceleration that occurs in the directions of the X-axis, Y-axis, and Z-axis due to movement of the electronic device 1. The acceleration sensor 40 may be a sensor having a sensor element made of, for example, ceramic, silicon, or the like.

[0055] The angular velocity sensor 50 detects angular velocities around the X-axis, Y-axis, and Z-axis. The angular velocity sensor 50 can detect angular velocities around the X-axis, Y-axis, and Z-axis caused by movement of the electronic device 1. The angular velocity sensor 50 may be, for example, a high-precision sensor having a sensor element made of quartz, or may be a capacitance sensor formed by processing a silicon substrate using MEMS technology. MEMS stands for Micro Electro Mechanical Systems.

[0056] In the electronic device 1 of the second embodiment, the measurement processing terminal 20 includes a time measurement unit 21, a control unit 22, and a movement distance calculation unit 23. The functions of the time measurement unit 21 and the control unit 22 are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0057] The travel distance calculation unit 23 calculates the travel distance MD of the electronic device 1 from the ith positioning time to the (i+N-1)th positioning time by, for example, a known inertial navigation method based on the three-axis acceleration detected by the acceleration sensor 40 and the three-axis angular velocity detected by the angular velocity sensor 50. i,i+N-1 For example, if the integer i is 1, the travel distance calculation unit 23 calculates the travel distance MD from the first positioning time to the Nth positioning time. 1,N Calculate.

[0058] In this way, the acceleration sensor 40, the angular velocity sensor 50, and the movement distance calculation unit 23 function as a detection unit 100 that detects the movement distance of the electronic device 1.

[0059] In the electronic device 1 of the second embodiment, the GNSS receiving terminal 10 includes a positioning unit 11, an output unit 12, and a determination unit 13.

[0060] The positioning unit 11 performs the same process as in the first embodiment to obtain the first to Nth positioning residuals Δmd1 to Δmd N and the first to (N-1)th distances D1 to D N-1 In the second embodiment, the positioning unit 11 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 An index INDX for evaluating the positioning environment in which the first to Nth positioning are performed based on the above. 1,N Calculate.

[0061] The determination unit 13 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to (N-1th) distances D1 to D N-1 and the travel distance MD 1,N In this embodiment, the determining unit 13 determines the positioning environment based on the index INDX calculated by the positioning unit 11. 1,N Specifically, the determining unit 13 determines the positioning environment at the time of the first to Nth positioning based on the index INDX. 1,N is equal to or less than a predetermined threshold value TH set by the control unit 22 of the measurement processing terminal 20. That is, the determination unit 13 determines whether the index INDX 1,N is compared with the threshold value TH, and the indicator INDX 1,N If the index INDX is equal to or smaller than the threshold value TH, the determination unit 13 determines that the positioning environment at the time of the first to Nth positioning is good, and outputs a high-level enable signal EN. 1,N If is greater than the threshold value TH, it is determined that the positioning environment at the time of the first to Nth positioning is not good, and a low level enable signal EN is output.

[0062] In this embodiment, the determination unit 13 calculates the first to Nth positioning residuals Δmd1 to Δmd N and the average value of the 1st to N-1th distances D1 to D N-1 and the cumulative value of the travel distance MD 1,N For example, the determining unit 13 determines the positioning environment based on the first to N-th positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The sum of the cumulative value of and the travel distance MD 1,N The positioning environment may be determined based on the difference between the index INDX and the 1,N are the 1st to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The sum of the cumulative value of and the travel distance MD 1,N It may be the difference between

[0063]

number

[0064] After completing the (N+1)th positioning, the positioning unit 11 performs the same processing on the second to (N+1)th positioning as on the first to (N)th positioning, and calculates an index INDX 2,N+1 The positioning unit 11 performs the same processing as that performed on the first to Nth positionings for each of the positionings after the (N+2)th positioning to calculate an index INDX for evaluating the positioning environment of the kth to (k+N-1)th positioning values. k,k+N-1 That is, the positioning unit 11 calculates the index INDX each time positioning after the Nth positioning is completed, and the determination unit 13 updates the enable signal EN to high level or low level each time the index INDX is updated.

[0065] The function of the output unit 12 is the same as that in the first embodiment, and therefore a description thereof will be omitted.

[0066] Fig. 8 is a flowchart showing an example of the procedure of the process of determining the positioning environment by the positioning unit 11 and the determination unit 13 in the second embodiment. In Fig. 8, the same steps as those in Fig. 4 are denoted by the same reference numerals. As shown in Fig. 8, first, the positioning unit 11 performs the processes of steps S10 to S110. The processes of steps S10 to S100 have been explained above, and therefore their explanation will be omitted.

[0067] Next, if the integer i is equal to or greater than the integer N in step S110, the positioning unit 11 calculates the moving distance MD of the electronic device 1 from the (i-N+1)th positioning time to the ith positioning time in step S112. i-N+1,i Get.

[0068] Next, in step S122, the positioning unit 11 calculates the index INDX i-N+1,i The positioning residuals Δmd from the i-N+1th to the i-th i-N+1 ~Δmd i and the distance D between the i-N+1th and i-1th i-N+1 ~D i-1 The sum of the cumulative value of and the travel distance MD i-N+1,i For example, if the integer i matches the integer N in step S110, the positioning unit 11 calculates the difference between the index INDX and the integer N in step S122. 1,N Then, using the above equation (2), the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 The sum of the cumulative value of and the travel distance MD 1,N Calculate the difference between

[0069] Then, the positioning unit 11 performs the processes of steps S130 to S170. The processes of steps S130 to S170 have been explained above, so their explanation will be omitted.

[0070] In the electronic device 1 of the second embodiment described above, the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1st distances D1 to D N-1 and the travel distance MD of the electronic device 1 from the first positioning time to the Nth positioning time. 1,N The difference between the two is the indicator INDX1,N The positioning environment is determined as follows. The first to Nth positioning residuals Δmd1 to Δmd N The average value of the first to Nth positions PA1 to PA2 of the reception points obtained by N times of positioning is N The average error of the 1st to N-1th distances D1 to D N-1 The cumulative value of is the distance traveled by the electronic device 1 during N times of positioning and the first to Nth positions PA1 to PA2 of the reception points obtained by the N times of positioning. N Therefore, the index INDX 1,N In this case, regardless of whether the electronic device 1 is moving or not, the first to Nth positions PA1 to PA N Therefore, according to the electronic device 1 of the second embodiment, the index INDX 1,N By comparing the value with the threshold value TH, the positioning environment can be determined with high accuracy.

[0071] In addition, the electronic device 1 of the second embodiment has the same effects as the electronic device 1 of the first embodiment.

[0072] 3. Variations The present invention is not limited to the present embodiment, and various modifications are possible within the scope of the present invention.

[0073] For example, in each of the above embodiments, a clock signal generating device is given as an example of the electronic device 1, but the electronic device according to the present invention is not limited to a clock signal generating device. For example, the electronic device according to the present invention may be a timing signal generating device that outputs a timing signal other than a clock signal, or may be a terminal such as the GNSS receiving terminal 10 in each of the above embodiments.

[0074] In the first embodiment described above, the output unit 12 and the determination unit 13 are included in the GNSS receiving terminal 10, but as shown in Fig. 9 , they may be included in the measurement processing terminal 20. In the example of Fig. 9 , the positioning unit 11 included in the GNSS receiving terminal 10 outputs a timing signal PPS to the output unit 12 included in the measurement processing terminal 20. In addition, the positioning unit 11 outputs an index IND to the determination unit 13 included in the measurement processing terminal 20.

[0075] Similarly, in the second embodiment described above, the output unit 12 and the determination unit 13 are included in the GNSS receiver terminal 10, but they may be included in the measurement processing terminal 20 as shown in Fig. 10. In the example of Fig. 10, the positioning unit 11 included in the GNSS receiver terminal 10 outputs a timing signal PPS to the output unit 12 included in the measurement processing terminal 20. In addition, the positioning unit 11 outputs an index INDX to the determination unit 13 included in the measurement processing terminal 20.

[0076] In addition, in each of the above embodiments, the positioning unit 11 calculates the index IND, but the determination unit 13 may calculate the index IND or the index INDX. For example, the positioning unit 11 may calculate the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 and the first to Nth positioning residuals Δmd1 to Δmd N and the 1st to N-1th distances D1 to D N-1 and based on the index IND 1,N or the indicator INDX 1,N Alternatively, the positioning unit 11 may generate NMEA data including various information such as position information and time information of the positioning results, the number of captured satellites 2, and reception conditions such as satellite signal strength, and the like, and the determination unit 13 may calculate the index IND or the index INDX based on the NMEA data. NMEA is an abbreviation for National Marine Electronics Association.

[0077] The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0078] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0079] The following can be derived from the above-described embodiment and modifications.

[0080] One aspect of the electronic device is N is an integer equal to or greater than 2, an antenna for receiving a plurality of satellite signals transmitted from a plurality of satellites; a positioning unit that performs first to Nth positioning at different timings based on the plurality of satellite signals; a determination unit that determines a positioning environment in which the first to Nth positioning operations are performed, The positioning unit For each integer i between 1 and N, calculate an i-th positioning residual based on the distance between the i-th position of the reception point obtained by the i-th positioning and the positions of each of the plurality of satellites used in the i-th positioning and the propagation distance of each of the plurality of satellite signals used in the i-th positioning; For each integer i between 2 and N, calculate an (i-1)th distance, which is the distance from the (i-1)th position to the i-th position; The determination unit The positioning environment is determined based on the first to N-th positioning residuals and the first to N-1th distances.

[0081] This electronic device determines the positioning environment for N positioning operations based on first to N-th positioning residuals obtained by N positioning operations and first to N-1th distances indicating the distance the reception point moved at each positioning operation. Each of the first to N-th positioning residuals reflects the position error of the reception point obtained by each positioning operation, and each of the first to N-1th distances reflects the variation in the position of the reception point obtained by each positioning operation when the position of the electronic device is fixed. Therefore, the first to N-th positioning residuals and the first to N-1th distances tend to increase due to deterioration in positioning accuracy caused by the effects of multipath and attenuation of received signals, etc. This electronic device therefore makes it possible to accurately determine the positioning environment based on the first to N-th positioning residuals and the first to N-1th distances. In particular, this electronic device does not use the electric field strength of the received signal or the number of visible satellites as indicators for determining the positioning environment, so it can accurately determine the positioning environment even in cases where, for example, the electric field strength of the received signal is high but the positioning accuracy deteriorates due to the effects of multipath.

[0082] In one aspect of the electronic device, The determining unit may determine the positioning environment based on an average value of the first to N-th positioning residuals and an accumulated value of the first to N-1th distances.

[0083] In this electronic device, the average value of the first to Nth positioning residuals reflects the average error in the positions of the reception points obtained by N number of positioning measurements, and the cumulative value of the first to N-1th distances reflects the sum of the variations in the positions of the reception points obtained by N number of positioning measurements when the position of the electronic device is fixed. Therefore, according to this electronic device, the positioning environment can be determined with high accuracy based on the average value of the first to Nth positioning residuals and the cumulative value of the first to N-1th distances.

[0084] In one aspect of the electronic device, The determining unit may determine the positioning environment based on the sum of an average value of the first to N-th positioning residuals and an accumulated value of the first to N-1th distances.

[0085] According to this electronic device, the sum of the average value of the first to Nth positioning residuals and the cumulative value of the first to N-1th distances reflects the average error and variation in the positions of the reception points obtained by N positioning operations, so the positioning environment can be determined with high accuracy.

[0086] In one aspect of the electronic device, When the plurality of satellites used in the i-th positioning are designated as 1st to M-th satellites, the plurality of satellite signals used in the i-th positioning are designated as 1st to M-th satellite signals transmitted from the 1st to M-th satellites, and for each integer j between 1 and M, the difference between the distance between the i-th position and the j-th satellite position and the propagation distance of the j-th satellite signal is designated as the j-th residual, The i-th positioning residual may be a standard deviation of the first to M-th residuals.

[0087] One aspect of the electronic device is: a detection unit that detects a moving distance of the electronic device; The determination unit may determine the positioning environment based on a difference between the moving distance and the sum of an average value of the first to N-th positioning residuals and an accumulated value of the first to N-1th distances.

[0088] In this electronic device, the average value of the first to Nth positioning residuals reflects the average error in the positions of the reception points obtained by N positioning operations, and the cumulative value of the first to N-1th distances reflects the distance the electronic device has moved during the N positioning operations and the sum of the variations in the positions of the reception points obtained by the N positioning operations. Therefore, the difference between the sum of the average value of the first to Nth positioning residuals and the cumulative value of the first to N-1th distances and the movement distance of the electronic device detected by the detection unit reflects the sum of the average error and the variations in the positions of the reception points obtained by N positioning operations, regardless of whether the electronic device is moving. Therefore, according to this electronic device, it is possible to accurately determine the positioning environment based on the difference between the sum of the average value of the first to Nth positioning residuals and the cumulative value of the first to N-1th distances and the movement distance of the electronic device.

[0089] One aspect of the electronic device is: a time measurement unit that measures time; The positioning device may further include an output unit that outputs a timing signal synchronized with the time of one of the plurality of satellites to the time measurement unit in accordance with the result of the determination of the positioning environment by the determination unit.

[0090] This electronic device can accurately measure time based on an accurate timing signal synchronized with the time of one of multiple satellites, depending on the positioning environment.

[0091] In one aspect of the electronic device, the determination unit determines whether an index for evaluating the positioning environment is equal to or less than a predetermined threshold; The output unit may output the timing signal to the time measurement unit when the index is equal to or smaller than a predetermined threshold value.

[0092] This electronic device can accurately measure time based on an accurate timing signal obtained when the positioning environment is good. [Explanation of symbols]

[0093] 1...electronic device, 2...satellite, 10...GNSS receiving terminal, 11...positioning unit, 12...output unit, 13...determination unit, 20...measurement processing terminal, 21...time measurement unit, 22...control unit, 23...travel distance calculation unit, 30...antenna, 40...acceleration sensor, 50...angular velocity sensor, 100...detection unit, 211...atomic oscillator

Claims

1. N is an integer equal to or greater than 2, an antenna for receiving a plurality of satellite signals transmitted from a plurality of satellites; a positioning unit that performs first to Nth positioning at different timings based on the plurality of satellite signals; a determination unit that determines a positioning environment in which the first to Nth positioning operations are performed, The positioning unit For each integer i between 1 and N, an i-th positioning residual is calculated based on the distance between the i-th position of the reception point obtained by the i-th positioning and the positions of each of the plurality of satellites used in the i-th positioning, and the propagation distance of each of the plurality of satellite signals used in the i-th positioning; For each integer i between 2 and N, calculate the (i-1)th distance, which is the distance from the (i-1)th position to the i-th position; The determination unit The electronic device determines the positioning environment based on the first to N-th positioning residuals and the first to N-1-th distances.

2. In claim 1, The determination unit determines the positioning environment based on an average value of the first to N-th positioning residuals and an accumulated value of the first to N-1th distances.

3. In claim 2, The determination unit determines the positioning environment based on a sum of an average value of the first to N-th positioning residuals and a cumulative value of the first to N-1th distances.

4. In claim 3, When the plurality of satellites used in the i-th positioning are designated as 1st to M-th satellites, the plurality of satellite signals used in the i-th positioning are designated as 1st to M-th satellite signals transmitted from the 1st to M-th satellites, respectively, and for each integer j between 1 and M, the difference between the distance between the i-th position and the j-th satellite position and the propagation distance of the j-th satellite signal is designated as the j-th residual, The electronic device, wherein the i-th positioning residual is the standard deviation of the first to M-th residuals.

5. In claim 1, a detection unit that detects a moving distance of the electronic device; The determination unit determines the positioning environment based on a difference between the sum of an average value of the first to Nth positioning residuals and an accumulated value of the first to N-1th distances, and the movement distance.

6. In claim 1, a time measurement unit that measures time; an output unit that outputs a timing signal synchronized with the time of one of the plurality of satellites to the time measuring unit in accordance with a result of the positioning environment determined by the determination unit.

7. In claim 6, the determination unit determines whether an index for evaluating the positioning environment is equal to or less than a predetermined threshold; The output unit outputs the timing signal to the time measurement unit when the index is equal to or smaller than a predetermined threshold.

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