JP2010032235A - Positioning system, control method for the positioning system, and control program for the positioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein with a method for selecting satellite radiowaves, by fixing a threshold wherein a conditional expression is likely to become complex, regarding threshold setting and its determination, when a threshold is to be added which is a new selection condition for the satellite radiowaves. <P>SOLUTION: An observation vector generating part 16 generates an observation vector 20a, based on observation information on received satellite radiowaves. Then, a determination part 17 determines whether reception conditions are satisfactory, based on the observation vector 20a and a plurality of reference vectors 20b previously stored in a storage part 20 for determining whether the reception conditions are satisfactory. A positioning part 18 carries out a positioning processing, based on whether the reception conditions are determined as being satisfactory. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positioning device, a positioning device control method, and a positioning device control program.

GPS (Global Positioning S) that uses the positioning information satellite to measure the current position of the positioning device
ystem) is widely used. However, when the satellite radio wave from the position information satellite does not reach the positioning device as a direct wave but arrives as an indirect wave reflected on a building or the like (hereinafter referred to as a multipath), this is due to the influence of the multipath or the like. There is a problem that an error occurs in the positioning process and the positioning accuracy is greatly reduced. For this reason, various techniques for eliminating the adverse effects of multipath and the like have been proposed. For example, in Patent Document 1 below, a threshold value of a reception CN that can be used for positioning calculation is determined according to the reception environment of the positioning device. Based on this threshold, it is determined whether the received satellite radio waves are adversely affected by multipath or the like. In Patent Document 2 below, a threshold for selecting a satellite radio wave used for positioning calculation is determined based on a received signal level of a position information satellite whose elevation angle is a predetermined angle or more among position information satellites being received. ing.

JP 2003-139842 A JP 2003-149315 A

However, in the method of determining the threshold value based on the received CN and the elevation angle of the position information satellite and selecting the satellite radio wave as described in Patent Document 1 and Patent Document 2, the satellite radio wave is added to the above-described threshold value. If it is attempted to further add a threshold value as a new selection condition, there is a possibility that a conditional expression related to the setting and determination of the threshold value becomes complicated. For this reason, it has been difficult to flexibly add an effective threshold value as a satellite radio wave selection condition in accordance with the reception environment of the positioning device, thereby improving the positioning accuracy.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A positioning device that receives a satellite radio wave of a position information satellite and performs a positioning process, and an observation vector generation unit that generates an observation vector whose element is observation information based on the received satellite radio wave;
A storage unit that stores a plurality of predetermined reference information, which serves as a reference for determining the quality of the received state of the received satellite radio wave, the generated observation vector, and the stored plurality of reference information A determination unit that determines whether the reception state is good or not, and a positioning unit that selects the satellite radio wave based on the determined reception state and performs the positioning process. Positioning device.

According to the positioning device described above, the observation vector generation unit generates an observation vector based on the received observation information of the satellite radio wave. Next, the determination unit determines the quality of the reception state based on this observation vector and a plurality of pieces of reference information for determining the quality of the reception state stored in advance in the storage unit. And a positioning part selects a satellite radio wave based on the quality of the determined receiving state, and performs a positioning process.
Since the positioning device determines the quality of the reception state based on the observation vector based on the received observation information and a plurality of reference information stored in advance, changes to the elements of the observation information and each reference information, etc. Thus, it is possible to easily cope with a change in the condition for determining whether or not the reception state is good. In addition, by setting each reference information stored in advance to contents corresponding to various reception environments of the positioning device, it is possible to determine whether the reception state in various reception environments is good or bad. As a result, satellite radio wave selection conditions can be flexibly set according to the receiving environment of the positioning device, and positioning accuracy can be improved.

[Application Example 2]
Each of the plurality of reference information is a reference vector composed of the same elements as the observation information, and the determination unit is a similarity calculation unit that calculates the similarity between the observation vector and each of the reference vectors, The reference vector having the highest calculated similarity and the similarity higher than a predetermined threshold is selected from the respective reference vectors, and based on reception environment information corresponding to the selected reference vector And a reception environment determination unit that determines whether the reception state is good or bad.

According to the positioning device described above, the similarity calculation unit calculates the similarity between the observation vector and each reference vector. Then, the reception environment determination unit selects a reference vector having the highest similarity and higher than a predetermined threshold, and determines the quality of the reception state based on the reception environment information.
Since the positioning device selects the reference vector having the highest similarity to the observation vector, it can acquire the reception environment information of the reference vector that best matches the observation information of the received satellite radio wave. Further, by selecting a similarity higher than a predetermined threshold, it is possible to avoid selection of a reference vector that is less compatible with observation information.

[Application Example 3]
The positioning apparatus according to claim 1, wherein the similarity calculation unit calculates the similarity using an inner product of the observation vector and the respective reference vectors.

According to the positioning device described above, the similarity can be easily calculated with a small amount of calculation by calculating the similarity using the inner product of the observation vector and each reference vector.

[Application Example 4]
The reception environment information includes an open sky environment, an indoor environment, and a multipath environment.
Information on at least one environment is included in the positioning device.

According to the positioning device described above, the reception environment information includes information in at least one of an open sky environment, an indoor environment, and a multipath environment, thereby acquiring information in various reception environments of the positioning device. Can do.

[Application Example 5]
The positioning device according to claim 1, wherein the reception environment information includes either information indicating that the reception state is good or information indicating that the reception state is bad.

According to the positioning device described above, the reception environment information includes either information indicating that the reception state is good or information indicating that the reception state is good, so that the quality of the reception state can be easily acquired.

[Application Example 6]
Each of the plurality of pieces of reference information is a probability model expressing characteristics of the observation information serving as a reference, and the determination unit calculates an output probability in the respective probability model for the observation vector. And a reception environment corresponding to the selected probability model, the probability model having the highest calculated output probability and the probability model having the output probability higher than a predetermined threshold is selected from the respective probability models And a reception environment determination unit that determines whether the reception state is good or not based on information.

According to the positioning device described above, the output probability calculation unit calculates the output probability in each probability model for the observation vector. Then, the reception environment determination unit selects the probability model having the highest output probability that is higher than a predetermined threshold value, and determines the quality of the reception state based on the reception environment information.
Since the positioning device selects the probability model with the highest output probability for the observation vector, it can acquire the reception environment information of the probability model that best matches the observation information of the received satellite radio waves. In addition, by setting the output probability higher than the predetermined threshold, it is possible to avoid selection of a probability model having low suitability for observation information.

[Application Example 7]
The positioning apparatus as described above, wherein the probability model is expressed by a multidimensional normal distribution.

According to the positioning device described above, a probability model expressed by a multidimensional normal distribution can be applied.

[Application Example 8]
The positioning device includes at least one of information on an elevation angle of the position information satellite, signal intensity of the satellite radio wave, continuity of the observation information, and freshness information.

[Application Example 9]
A positioning apparatus control method for performing positioning processing by receiving satellite radio waves of a position information satellite, and a plurality of predetermined reference information serving as a criterion for determining whether the reception status of the received satellite radio waves is good or not In the stored state, based on the observation vector generation step of generating an observation vector having the observation information based on the received satellite radio wave as an element, the generated observation vector and the plurality of stored reference information And a positioning step for determining whether the reception state is good and a positioning step for performing the positioning process by selecting the satellite radio wave based on the determined good / bad reception state. Control method of the device.

According to the above-described positioning apparatus control method, in the observation vector generation step, an observation vector is generated based on the received satellite radio wave observation information. Next, in the determination step, the quality of the reception state is determined based on this observation vector and a plurality of pieces of reference information for determining the quality of the reception state stored in advance. Then, in the positioning step, a positioning process is performed by selecting satellite radio waves based on the judged reception quality.
Since the positioning device determines the quality of the reception state based on the observation vector based on the received observation information and a plurality of reference information stored in advance, changes to the elements of the observation information and each reference information, etc. Thus, it is possible to easily cope with a change in the condition for determining whether or not the reception state is good. In addition, by setting each reference information stored in advance to contents corresponding to various reception environments of the positioning device, it is possible to determine whether the reception state in various reception environments is good or bad. As a result, satellite radio wave selection conditions can be flexibly set according to the receiving environment of the positioning device, and positioning accuracy can be improved.

[Application Example 10]
A positioning apparatus control program that receives a satellite radio wave of a position information satellite and performs a positioning process, and a plurality of predetermined reference information serving as a reference for determining whether the reception state of the received satellite radio wave is good or not In the stored state, based on the observation vector generation function for generating an observation vector having the observation information based on the received satellite radio wave as an element, the generated observation vector and the plurality of stored reference information A positioning function for determining whether the reception state is good and a positioning function for selecting the satellite radio wave and performing the positioning process based on the determined good / bad reception state. Device control program.

According to the control program of the positioning device described above, the observation vector is generated based on the received observation information of the satellite radio wave by the observation vector generation function. Next, the determination function determines the quality of the reception state based on this observation vector and a plurality of reference information for determining the quality of the reception state stored in advance. Then, the positioning function is performed by selecting a satellite radio wave based on the determined reception quality.
Since the positioning device determines the quality of the reception state based on the observation vector based on the received observation information and a plurality of reference information stored in advance, changes to the elements of the observation information and each reference information, etc. Thus, it is possible to easily cope with a change in the condition for determining whether or not the reception state is good. In addition, by setting each reference information stored in advance to contents corresponding to various reception environments of the positioning device, it is possible to determine whether the reception state in various reception environments is good or bad. As a result, satellite radio wave selection conditions can be flexibly set according to the receiving environment of the positioning device, and positioning accuracy can be improved.

(First embodiment)
The positioning device according to the first embodiment will be described below with reference to the drawings.

<Outline of positioning device>
First, an outline of the positioning device according to the first embodiment will be described.
FIG. 1 is a schematic diagram illustrating an example of a positioning device 10 according to the first embodiment. The positioning device 10 shown in the figure is a portable telephone device that can be carried and carried by a user, for example. Positioning device 10
Are GPS satellites 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1 as position information satellites.
h, etc., signals S1, S2, S3, S4, S5, S6, S7, which are the respective satellite radio waves.
S8 etc. are received, the navigation message contained in each signal is analyzed, and a positioning process is performed.

At this time, the positioning device 10 receives the signal S1 and the like from the GPS satellite 1a and the like in various reception environments such as an open sky environment, an indoor environment, and a multipath environment as shown in FIG. Here, in the open sky environment, the obstacle that shields the signal S1 and the like is the positioning device 10.
It shows an environment that does not exist around. The indoor environment indicates an indoor environment where the positioning device 10 is located in the building 2a. The multipath environment indicates an environment in which the building 2b and the like are located around the positioning device 10 and the possibility of receiving the multipath is high.

The positioning device 10 has a function of determining whether or not the reception state of the signal S1 or the like received under such various reception environments is good and selecting an available GPS satellite 1a or the like. The positioning device 10 is not limited to a portable telephone device, and for example, a PHS (Personal Handy-phone Syste)
m), PDA (Personal Digital Assistance), portable navigation, car navigation, etc.

Next, a positioning method in the positioning device 10 will be described.
FIG. 2 is a conceptual diagram illustrating an example of a positioning method. As shown in the figure, for example, a GPS satellite 1a
And a positioning device 10 include a portion that is an integral multiple of the length (about 300 kilometers (km)) of a C / A (Coarse / Access) code, which is a basic unit of GPS positioning, and a fractional portion. .
The total of the length of the integral multiple of these C / A codes and the length of the fractional part is the pseudo distance. The positioning device 10 performs positioning using pseudoranges for three or more GPS satellites 1a and the like. Here, the code fraction C / Aa, which is the fraction part of the C / A code, is referred to as a code phase. For example, the code phase can be indicated by the number of the 1023 chip of the C / A code, or can be indicated in terms of distance. When calculating the pseudo distance, the code phase is converted into a distance.

Here, in the positioning device 10, the phase of the replica C / A code shown in FIG.
Correlation processing is performed while moving in one direction. At this time, the positioning device 10 performs the correlation process while changing the synchronization frequency. This correlation processing is composed of coherent processing and incoherent processing described later. The phase with the maximum correlation integrated value is the code phase.

FIG. 3 is an explanatory diagram of the correlation processing. Coherent is a process for obtaining a correlation between the C / A code received by the positioning device 10 and the replica C / A code. The replica C / A code is a code generated in the positioning device 10. For example, as shown in FIG. 3, if the coherent time is 5 milliseconds (msec), C /
A correlation value between the A code and the replica C / A code is calculated. As a result of this coherent processing, a correlated phase (code phase) and a correlation value are output. Incoherent
Accumulated correlation values (incoherent values) by accumulating the correlation values of coherent results
Is a process for calculating. As a result of the correlation process, the code phase and the correlation integrated value output by the coherent process are output.

FIG. 4 is a diagram illustrating an example of the relationship between the correlation integrated value P and the code phase CP. The code phase CP1 corresponding to the maximum value Pmax of the correlation integrated value P shown in the figure is the code phase of the replica C / A code, that is, the code phase of the C / A code. And positioning device 1
0 is, for example, a code phase that is a half chip away from the code phase CP1,
The correlation integrated value with the smaller correlation integrated value is set as a noise integrated correlation value Pnoise. In the present embodiment, in the positioning device 10, a value obtained by dividing the difference between Pmax and Pnoise by Pmax is defined as the signal strength XPR.

<Functional configuration of positioning device>
Next, the functional configuration of the positioning device 10 according to the first embodiment will be described.
FIG. 5 is a block diagram illustrating a functional configuration example of the positioning device 10. As shown in the figure, the positioning device 10 includes a control unit 11, a display unit 12, an operation unit 13, a time measurement unit 14, a satellite reception unit 15, an observation vector generation unit 16, a determination unit 17, a positioning unit 18, and a storage unit 20. Etc. are provided.

The control unit 11 includes a CPU (Central Processing Unit), a RAM (Random Acce) (not shown).
ss Memory), ROM (Read Only Memory), and the like, and comprehensively controls each unit in the positioning device 10.
The display unit 12 displays various information on an LCD (Liquid Crystal Display), for example.
The operation unit 13 receives an operation instruction from the user of the positioning device 10 by using, for example, a button or the like, and supplies a signal corresponding to the operation instruction to the control unit 11.
The timekeeping unit 14 includes a timekeeping mechanism, and measures time, a predetermined time interval, and the like.
The satellite receiver 15 receives a signal S1 from each GPS satellite 1a or the like via an antenna (not shown).
Etc.

The observation vector generation unit 16 generates an observation vector 20a whose element is a measurement as observation information based on the signal S1 received by the satellite reception unit 15. This observation vector 20
a is generated for each received signal S1 and the like and stored in the storage unit 20. In the present embodiment, three items of “XPR”, “elevation angle”, and “MeasAge” are used as the types of measurements that are elements of the observation vector 20a. XPR is the value of the signal strength obtained from the correlation integrated value when calculating the pseudo distance as described above. The elevation angle indicates the elevation angle of the GPS satellite 1a or the like with the current position of the positioning device 10 as a reference. MeasAge indicates the freshness of the measurement with respect to the positioning accuracy by comparing the measured value and the predicted value of the code phase. Meas
The smaller the Age value, the higher the freshness of the measurement.
Note that the types of measurement as observation information are “XPR”, “elevation angle” and “Meas”.
For example, a part of the items “XPR”, “elevation angle”, and “MeasAge” are deleted, or the measurement is continuously performed with respect to the positioning accuracy by comparing the measured value and the predicted value of the code phase. The configuration of the measurement may be changed by adding another item related to the signal from the GPS satellite, such as adding a sex item.

The determination unit 17 includes a similarity calculation unit 17a and a reception environment determination unit 17b. The determination unit 17 obtains the reception environment information 20c by comparing the observation vector 20a generated by the observation vector generation unit 16 with a plurality of reference vectors 20b. Based on the reception environment information 20c, the quality of the received state of the received signal S1 or the like is determined. The reference vector 20b and the reception environment information 20c are stored in advance in the storage unit 20.

The similarity calculation unit 17 a in the determination unit 17 includes an observation vector 20 a and each reference vector 20.
The similarity with b is calculated.
Here, an example of processing for calculating the similarity will be described. N for one observation vector 20a
When the dimension vector X and one reference vector 20b are n-dimensional vectors Y, these two
The dot product between two vectors is defined as

ここで、θは２つのベクトルのなす角を表し、｜Ｘ｜及び｜Ｙ｜は各ベクトルＸ、Ｙの
ノルムを表す。

Here, θ represents an angle formed by two vectors, and | X | and | Y | represent norms of the vectors X and Y.

  From Equation 1, the angle θ formed by the two vectors can be expressed by Equation 2.

In other words, the similarity between the observation vector 20a and the reference vector 20b increases as θ here approaches 0. Conversely, the closer θ is to π, the lower the similarity between the observed vector 20a and the reference vector 20b.

Based on the similarity to each reference vector 20b calculated by the similarity calculation unit 17a, the reception environment determination unit 17b in the determination unit 17 has the highest similarity among the reference vectors 20b and the similarity is predetermined. A reference vector 20b that is higher than the threshold value is selected.

FIG. 6A is a diagram illustrating an example of one observation vector 20a, and FIG. 6B is a diagram illustrating an example of a plurality of reference vectors 20b. In FIG. 6B, the similarity between the observation vector 1 shown in FIG. 6A and the reference vectors 1 to 6 shown in FIG. In FIG. 6B, among the reference vectors 1 to 6, the similarity “0.025587” of the reference vector 3 is 0 most.
Since it is close to, the similarity is the highest. Here, as the predetermined threshold, for example, “
When “0.3” is set, the similarity “0.025587” of the reference vector 3 is the threshold “0.3”.
"Is closer to 0 than"", the similarity is higher than the threshold.

As a result, the reception environment determination unit 17b selects the reference vector 3 as the reference vector 20b having the highest similarity and the similarity being higher than the predetermined threshold among the reference vectors 20b. Then, the reception environment determining unit 17b determines whether the reception state of the received signal of the observation vector 1 is good or not based on the reception environment information 20c corresponding to the selected reference vector 3.

FIG. 7 is a diagram illustrating an example of the reception environment information 20c corresponding to the reference vector 20b. In the drawing, reference vectors 1 to 3 indicate “good reception state”, and reference vectors 4 to 6 indicate “bad reception state”. The reference vectors for “good reception state” and “bad reception state” are divided into “open sky environment”, “indoor environment”, and “multipath environment”.
When the reference vector 3 is selected in the figure, the reception environment determination unit 17b acquires reception environment information 20c indicating “(good reception state) multipath environment” corresponding to the reference vector 3. Then, the reception environment determination unit 17b determines that the reception signal of the observation vector 1 is a signal received in a good reception state in a multipath environment.
Note that the types of the reference vector 20b and the reception environment information 20c are not limited to this, and the information regarding the quality of the reception state, the information regarding the reception environment, and the like may be further subdivided or conversely omitted. good.

The positioning unit 18 selects a GPS satellite to be used on the basis of the reception status information of each observation vector 20a determined by the reception environment determination unit 17b, and analyzes the navigation message included in the signal from the GPS satellite. To perform positioning processing.
The storage unit 20 is, for example, an EEPROM (Electrically Erasable Programmable Read-Only
Memory) or a non-volatile memory such as a flash memory, which stores the above-described observation vectors 20a, reference vectors 20b, reception environment information 20c, and the like.

<Operation in positioning device>
Next, the operation of the positioning device 10 according to the first embodiment will be described.
FIG. 8 is a flowchart illustrating an operation example of the positioning device 10 according to the first embodiment. The flowchart shown in the figure is started when the operation unit 13 receives an operation instruction for starting the positioning process from the user.

First, in step S110, the positioning device 10 receives signals S1 and the like from the GPS satellites 1a and the like by the satellite receiver 15.

In step S120, the positioning device 10 causes the observation vector generation unit 16 to execute step S120.
An observation vector 20 a is generated for one of the signals S 1 and the like received at 110 and stored in the storage unit 20.

In step S130, the positioning device 10 uses the similarity calculation unit 17a in the determination unit 17 to determine the similarity between one of the observation vectors 20a generated in step S120 and each reference vector 20b stored in the storage unit 20. calculate.

In step S140, the positioning device 10 searches the similarity that is highest and higher than the predetermined threshold from the similarities calculated in step S130 by the reception environment determination unit 17b in the determination unit 17, A reference vector 20b is selected.

In step S150, the positioning device 10 causes the reception environment determination unit 17b to execute step S1.
The reception environment information 20c corresponding to the reference vector 20b selected in 40 is acquired.
Then, based on the reception environment information 20c, the quality of the reception state of the reception signal of the observation vector 20a generated in step S120 is determined.

In step S160, the positioning device 10 receives the signal S1 received in step S110.
It is determined whether or not all the processes are completed. When finished, the next step S
Proceed to 170. On the other hand, if not finished, that is, if there is an unprocessed signal, step S
The processing from 120 to S150 is repeated.

In step S170, the positioning apparatus 10 uses the positioning unit 18 based on the information on the quality of the reception state of each observation vector 20a determined in step S150.
Select the satellite and perform the positioning process.

Note that step S120 corresponds to an observation vector generation step and an observation vector generation function. Moreover, said step S130-S150 is corresponded to a determination process and a determination function.
Step S170 corresponds to a positioning process and a positioning function.

As described above, in the positioning device 10 according to the present embodiment, when determining whether the reception state of the signal S1 from each GPS satellite 1a or the like is good or bad, based on the similarity between the observation vector 20a and the reference vector 20b. to decide. In the present embodiment, items “XPR”, “elevation angle”, and “MeasAge”, which are elements of the observation vector 20a and the reference vector 20b, are used as conditions for determining whether the reception state is good or bad. Here, when these determination conditions are to be changed to another item, it can be easily dealt with by changing the configuration of vector elements. Further, for the reference vector 20b for which the similarity is calculated, for example, whether the reception state such as “good reception state” or “bad reception state” is good, “open sky environment”, “indoor environment”, “multipath” By providing various combinations according to various reception environments such as “environment”, the quality of the reception state can be determined finely and accurately according to the reception environment of the positioning device 10.

(Second Embodiment)
The positioning device according to the second embodiment will be described below with reference to the drawings.

The positioning device 50 according to the second embodiment is a positioning device 1 according to the first embodiment shown in FIGS.
The same outline and positioning method as in the case of 0 can be applied.

FIG. 9 is a block diagram illustrating a functional configuration example of the positioning device 50 according to the second embodiment. As shown in the figure, the positioning device 50 is similar to the positioning device 10 according to the first embodiment shown in FIG.
A control unit 11, a display unit 12, an operation unit 13, a time measuring unit 14, a satellite receiving unit 15, an observation vector generating unit 16, a determining unit 17, a positioning unit 18, a storage unit 20, and the like are provided. In the case of the positioning device 50, the configuration of the determination unit 17 and the storage unit 20 is different from the positioning device 10 according to the first embodiment.

The determination unit 17 in the positioning device 50 includes an output probability calculation unit 17c and a reception environment determination unit 17b. Here, the determination unit 17 compares the observation vector 20a generated by the observation vector generation unit 16 with the plurality of probability models 20d, thereby receiving the reception environment information 2
0c is acquired. Based on the reception environment information 20c, the quality of the received state of the received signal S1 or the like is determined. The probability model 20d and the reception environment information 20c are stored in the storage unit 20 in advance. In the present embodiment, the probability model 20d is expressed by a multidimensional normal distribution including elements of each measurement in the observation vector 20a, but is not limited thereto.

The output probability calculation unit 17c in the determination unit 17 calculates the output probability of the observation vector 20a in each probability model 20d.
Here, an example of processing for calculating the output probability will be described. When one observation vector 20a is an n-dimensional vector X and a probability model 20d for calculating an output probability is a probability model i, the output probability P (X) output from the probability model i of the vector X is defined as in Equation 3. Is done.

Based on the output probability in each probability model 20d calculated in the output probability calculation unit 17c, the reception environment determination unit 17b in the determination unit 17 has the highest output probability among the probability models 20d and the output probability is predetermined. The probability model 20d higher than the threshold value is selected. Then, the reception environment determining unit 17b determines whether the reception state of the reception signal of the corresponding observation vector 20a is good or not based on the reception environment information 20c corresponding to the selected probability model 20d.

FIG. 10 is a diagram illustrating an example of the reception environment information 20c corresponding to the probability model 20d. In the figure, probability models 1 to 3 indicate “good reception state”, and probability models 4 to 6 indicate “bad reception state”. In addition, the probability models of “good reception state” and “bad reception state” are “open sky environment”, “indoor environment” and “multipath environment”, respectively.
It is divided into. Moreover, in FIG. 10, the output probability in each probability model 1-6 is described for description. In the figure, the output probability “20” of the probability model 3 among the probability models 1 to 6.
% "Is the highest. Here, for example, when “10%” is set as the predetermined threshold, the output probability “20%” of the probability model 3 is higher than the threshold “10%”.
When the probability model 3 is selected in FIG. 10, the reception environment determination unit 17 b acquires reception environment information 20 c indicating “(good reception state) multipath environment” corresponding to the probability model 3. Then, the reception environment determination unit 17b determines that the reception signal of the observation vector 1 is a signal received in a good reception state in a multipath environment.
Note that the types of the probability model 20d and the reception environment information 20c are not limited to this, and the information related to the quality of the reception state, the information related to the reception environment, and the like may be further subdivided or conversely omitted. good.

<Operation in positioning device>
Next, the operation in the positioning device 50 according to the second embodiment will be described.
FIG. 11 is a flowchart showing the operation of the positioning device 50 according to the second embodiment. In the flowchart shown in FIG. 11, the operations of steps S130, S140, and S150 in the flowchart of the positioning device 10 according to the first embodiment shown in FIG. 8 are replaced with the operations of steps S130A, S140A, and S150A, respectively.

In steps S110 and S120, the positioning device 50 receives signals S from the GPS satellites 1a and the like.
1 is received, and an observation vector 20 a is generated and stored in the storage unit 20.

In step S130A, the positioning device 50 outputs the output probability calculation unit 17c in the determination unit 17.
Thus, the output probability in each probability model 20d stored in the storage unit 20 is calculated for one of the observation vectors 20a generated in step S120.

In step S140A, the positioning device 50 receives the reception environment determination unit 17b in the determination unit 17.
Thus, the output probability that is highest and higher than the predetermined threshold is searched from among the output probabilities calculated in step S130A, and the probability model 20d is selected.

In step S150A, the positioning device 50 causes the reception environment determination unit 17b to execute step S150.
The reception environment information 20c corresponding to the probability model 20d selected in 140A is acquired. Based on this reception environment information 20c, the quality of the reception state of the reception signal of the observation vector 20a generated in step S120 is determined.

In steps S160 and S170, the positioning device 50 selects the GPS satellite to be used based on the reception status information of each observation vector 20a when the processing for all the signals S1 and the like received in step S110 is completed. To perform positioning processing.

Note that step S120 corresponds to an observation vector generation step and an observation vector generation function. Moreover, said step S130A-S150A is corresponded to a determination process and a determination function. Step S170 corresponds to a positioning process and a positioning function.

As described above, in the positioning device 50 according to the present embodiment, when determining whether the reception state of the signal S1 from each GPS satellite 1a or the like is good or bad, based on the output probability of the observation vector 20a in each probability model 20d. to decide. In the present embodiment, “XPR” and “elevation angle”, which are elements of the observation vector 20a and the probability model 20d, are used as conditions for determining whether the reception state is good or bad.
And the item “MeasAge” is used. Here, when trying to change these determination conditions to other items, it can be easily dealt with by changing the configuration of the elements of the vector and the probability model. Further, regarding the probability model 20d for which the output probability is calculated, for example, whether the reception state such as “good reception state” or “bad reception state” is good, “open sky environment”, “indoor environment”, “multipath” By providing various combinations according to various reception environments such as “environment”, the quality of the reception state can be determined finely and accurately according to the reception environment of the positioning device 50.

Schematic which shows the example of the positioning apparatus which concerns on 1st Embodiment. The conceptual diagram which shows the example of the positioning method. Explanatory drawing of a correlation process. The figure which shows the example of the relationship between a correlation integrated value and a code phase. The block diagram which shows the function structural example of a positioning apparatus. (A) is a figure which shows the example of an observation vector, (b) is a figure which shows the example of a reference | standard vector. The figure which shows the example of the reception environment information corresponding to a reference | standard vector. The flowchart which shows the operation example in the positioning apparatus which concerns on 1st Embodiment. The block diagram which shows the function structural example of the positioning apparatus which concerns on 2nd Embodiment. The figure which shows the example of the reception environment information corresponding to a probability model. The flowchart which shows the operation | movement in the positioning apparatus which concerns on 2nd Embodiment.

Explanation of symbols

1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h ... GPS satellites, 2a ... buildings, 2b ...
Building, 10, 50 ... Positioning device, 11 ... Control unit, 12 ... Display unit, 13 ... Operation unit, 14 ... Timekeeping unit, 15 ... Satellite reception unit, 16 ... Observation vector generation unit, 17 ... Determination unit, 17a ... Similar Degree calculation unit, 17b ... reception environment determination unit, 17c ... output probability calculation unit, 18 ... positioning unit, 20 ... storage unit,
20a ... observation vector, 20b ... reference vector, 20c ... reception environment information, 20d ... probability model, S1, S2, S3, S4, S5, S6, S7, S8 ... signal.

Claims (10)

A positioning device that performs positioning processing by receiving satellite radio waves from a location information satellite,
An observation vector generating unit that generates an observation vector whose element is observation information based on the received satellite radio wave;
A storage unit for storing a plurality of predetermined reference information, which serves as a reference for determining the quality of the received state of the received satellite radio waves;
A determination unit that determines the quality of the reception state based on the generated observation vector and the plurality of stored reference information;
And a positioning unit that selects the satellite radio wave and performs the positioning process based on the determined reception status. Each of the plurality of reference information is a reference vector composed of the same elements as the observation information,
The determination unit
A similarity calculator for calculating the similarity between the observation vector and the respective reference vectors;
The reference vector having the highest calculated similarity and the similarity higher than a predetermined threshold is selected from the respective reference vectors, and based on reception environment information corresponding to the selected reference vector The positioning apparatus according to claim 1, further comprising: a reception environment determination unit that determines whether the reception state is good or bad. The positioning device according to claim 2, wherein the similarity calculation unit calculates the similarity using an inner product of the observation vector and the respective reference vectors. The reception environment information includes an open sky environment, an indoor environment, and a multipath environment.
The positioning device according to claim 2 or 3, comprising information on at least one environment. The positioning device according to any one of claims 2 to 4, wherein the reception environment information includes either information indicating that the reception state is good or information indicating that the reception state is bad. Each of the plurality of pieces of reference information is a probability model expressing characteristics of the observation information serving as a reference,
The determination unit
For the observation vector, an output probability calculation unit that calculates an output probability in each of the probability models;
The probability model having the highest calculated output probability and having the output probability higher than a predetermined threshold is selected from the respective probability models, and based on reception environment information corresponding to the selected probability model The positioning apparatus according to claim 1, further comprising: a reception environment determination unit that determines whether the reception state is good or bad. The positioning apparatus according to claim 6, wherein the probability model is expressed by a multidimensional normal distribution. The observation information includes at least one of information on an elevation angle of the position information satellite, signal strength of the satellite radio wave, continuity of the observation information, and freshness information. A positioning device according to claim 1. A method for controlling a positioning device that performs positioning processing by receiving satellite radio waves from a position information satellite,
In a state where a plurality of predetermined reference information is stored, which is a reference for determining the quality of the received state of the received satellite radio wave,
An observation vector generation step of generating an observation vector having the observation information based on the received satellite radio wave as an element;
A determination step of determining pass / fail of the reception state based on the generated observation vector and the plurality of stored reference information;
And a positioning step of selecting the satellite radio wave and performing the positioning process based on the determined reception status. A control program for a positioning device that performs positioning processing by receiving satellite radio waves from a position information satellite,
In a state where a plurality of predetermined reference information is stored, which is a reference for determining the quality of the received state of the received satellite radio wave,
An observation vector generation function for generating an observation vector whose element is observation information based on the received satellite radio wave;
A determination function for determining the quality of the reception state based on the generated observation vector and the plurality of stored reference information;
A positioning apparatus control program, comprising: a positioning function that selects the satellite radio wave and performs the positioning process based on the determined reception status.

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