JP2008151611A - Positioning circuit, electronic device, positioning method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve altitude data used in two-dimensional positioning to reduce the amount of data and increase the search speed.
In the positioning calculation based on GPS satellite signals, three-dimensional positioning is first performed, and when the three-dimensional positioning fails, two-dimensional positioning based on the altitude obtained by searching the altitude table is performed. The altitude table is a data table in which the altitude is defined for each of the plurality of areas 50 set in the terrain, and includes an altitude table in which an altitude such as “100 m” is defined and a table without altitude in which the altitude is not defined. The area 50 has a rectangular shape whose size can be arbitrarily set, and a plurality of areas 50 are allowed to be superimposed (overlapped). Each altitude table is given a priority order in the descending order of altitude defined, and stored according to this priority order. The search of the altitude table is performed in the order of storage, that is, in the descending order of the defined altitude.
[Selection] Figure 3

Description

  The present invention relates to a positioning circuit, an electronic device, a positioning method, and a program.

  GPS (Global Positioning System), a type of satellite positioning system, sends out GPS satellite signals from each of multiple GPS satellites orbiting the earth orbit, and the GPS receiver calculates the current position based on the received GPS satellite signals. To do.

  Two radio waves of the L1 band (1575.42 MHz) and the L2 band (1227.6 MHz) having different frequencies are transmitted from the GPS satellite, but only the L1 band is permitted for consumer use. This L1 band GPS satellite signal is a signal that has been spread spectrum with a C / A (Coarse / Acquisition) code, which is a pseudo random signal (PRN) that differs for each satellite, and a navigation message. The navigation message includes almanac (satellite calendar) that is rough orbit information of all GPS satellites, ephemeris (orbit calendar) that is detailed orbit information of the GPS satellites, time information, and the like.

  Then, the GPS receiver captures and tracks the received GPS satellite signal, and decodes the navigation message included in the GPS satellite signal. Next, the current position is calculated based on the GPS satellite orbit information and time information included in the decoded navigation message. That is, from the difference between the transmission time of the GPS satellite signal from each GPS satellite and the reception time of the GPS satellite signal at the GPS receiver, the position of each GPS satellite at the time of transmission of the GPS satellite signal and each GPS from the GPS receiver Calculate the pseudorange to the satellite. Then, a simultaneous equation having four unknowns, that is, a three-dimensional position of the GPS receiver and a clock error between the GPS satellite and the GPS receiver, is established, and the current position is calculated by solving the simultaneous equations. At this time, the GPS receiver can calculate a three-dimensional position by receiving GPS satellite signals from at least four or more GPS satellites. This is because four of the three-dimensional position and the clock error between the GPS satellite and the GPS receiver are unknown.

  Such a GPS receiver is applied to various electronic devices such as a car navigation device. In the car navigation device, a navigation screen in which the current position measured at a predetermined time interval (for example, every one second) is plotted on a map is displayed on the display.

As described above, a GPS receiver needs to receive GPS satellite signals from four or more GPS satellites in order to calculate a three-dimensional position. When positioning is impossible, two-dimensional positioning is performed to calculate the two-dimensional position of latitude and longitude at an altitude acquired from predetermined map data. This map data is altitude data in which the altitude is set in association with each mesh obtained by dividing the map into meshes (see, for example, Patent Document 1).
JP 2003-57329 A

  The conventional altitude data (map data) used in two-dimensional positioning seems to have room for further improvement. That is, for example, in a data structure in which a map is divided into meshes and altitudes are associated with each mesh, the amount of data increases in proportion to the size of the target map range. Further, when searching for altitude data, for example, simply searching in the order in which data is stored has a very poor search efficiency, and a navigation device that measures and displays the current position in real time may cause a display delay. Also, there are places where the altitude should be defined and places that do not necessarily have to be defined according to the purpose of use of the current position. For example, since a car navigation device is mounted on a car, it may be mainly targeted at a place where a car such as a road enters, and a portable navigation device intended to be carried by a pedestrian, It is necessary to target a place that is wider than a car navigation device and that is likely to be entered by humans.

  The present invention has been made in view of the above circumstances, and aims to reduce the amount of data and increase the search speed by improving altitude data used for two-dimensional positioning.

  The first invention for solving the above-mentioned problems is that there is no altitude definition storing an altitude storage unit that memorizes altitudes in each area, and an area in which any altitude is not defined. Determine whether or not the region storage unit and the given approximate position are within the region stored in the region storage unit without altitude definition, and if it is within the stored region, the two-dimensional current position using the altitude If the position is not within the stored area, the altitude corresponding to the area including the approximate position of the areas where the altitude is stored in the altitude storage unit, the approximate position, and the satellite from the positioning satellite And a positioning circuit that measures a current position based on a signal.

  According to a ninth aspect of the present invention, a given approximate position stores an area in which the altitude is not defined and is within any one of the areas of the altitude storage unit in which the altitude of each area is stored. A determination step for determining whether or not the area is stored in the undefined area storage unit, and, if the result of the determination is that the area is stored in the undefined area storage unit, the two-dimensional using the altitude If the current position is not measured and is not within the stored area, the altitude corresponding to the area including the approximate position of the areas where the altitude is stored in the altitude storage unit, the approximate position, and the positioning satellite And a positioning step for positioning the current position based on the satellite signal.

  According to the first or ninth invention, the altitude of each region is stored in the altitude storage unit, and any region within each region stored in the altitude storage unit and the altitude is not defined is the altitude. None Stored in the area storage unit. If the given approximate position is in the area stored in the area storage unit without altitude, the two-dimensional current position using the altitude is not measured, and if not in the area, the altitude storage unit The current position is determined based on the altitude corresponding to the area including the approximate position of the areas in which is stored, the approximate position, and the satellite signal from the positioning satellite.

  In other words, if the approximate position is included in an area where the altitude is not defined, two-dimensional positioning using the altitude is not performed. If not included, the two-dimensional positioning based on the altitude of the area including the approximate position is not performed. Is done. Here, the area stored in the no-altitude area storage unit is, for example, a place within the area stored in the altitude storage unit, where the altitude changes relatively narrowly. When the altitude is stored for such a place, since the range where the same altitude can be set is narrow, it must be divided into a large number of narrow ranges in accordance with the change in altitude. However, by making such a place an area where the altitude is not defined, the data amount of the entire data stored in the altitude storage unit and the no altitude region storage unit is reduced.

  Further, although the current position is measured using the altitude corresponding to the area including the approximate position, a deviation between the approximate position and the actual position is inevitable. For this reason, in places where the altitude changes greatly in a relatively narrow range, even if there is a slight change in the approximate position, the altitude defined for the area including the position differs, and as a result, the error in the current position to be measured is large. Become. Therefore, by not defining the altitude for an area where the altitude change is large in a relatively narrow range, it is possible to avoid an error caused by the approximate position shift and improve the reliability of the current position measured.

  2nd invention is the positioning circuit of 1st invention, Comprising: The said altitude memory | storage part has memorize | stored the altitude of the area where the altitude on the earth should be memorize | stored, and the said positioning part is the said outline | summary When the position is not in any of the regions where the altitude is stored in the altitude storage unit, the positioning circuit does not measure the two-dimensional current position using the altitude.

  The tenth aspect of the invention is the positioning method of the ninth aspect of the invention, wherein the altitude storage unit stores the altitude of the area where the altitude on the earth should be stored, and the positioning step includes The positioning method is a step of not measuring the two-dimensional current position using the altitude when the approximate position is not in any of the regions where the altitude is stored in the altitude storage unit.

  Here, “the altitude on the earth” means, for example, an ellipsoidal height, an altitude above sea level, an altitude, or the like. According to the second or tenth invention, the altitude storage unit stores the altitude of the region where the altitude on the earth should be stored, and the approximate position is stored in the altitude storage unit. If it is not in the area, the two-dimensional current position is not measured using the altitude. That is, the altitude storage unit stores only the altitude of the area where the altitude should be stored. Thereby, reduction of the data amount memorize | stored in an altitude memory | storage part is implement | achieved. Here, the area where the altitude should be stored is, for example, whether it is an urban area or a residential area within a certain distance from the road, depending on the use of the current position to be measured (used for car navigation devices, etc.) It is designed based on whether or not.

  3rd invention is a positioning circuit of 1st or 2nd invention, Comprising: The said altitude memory | storage part matches the area specific information which specifies each area divided | segmented into the rectangular shape, and the altitude of the said area It is a positioning circuit memorized.

  According to the third aspect of the invention, the altitude storage unit stores the specific information for specifying each area divided into rectangular shapes and the altitude of the area in association with each other. Each area is divided into rectangular shapes, and the size can be arbitrarily set. As a result, for example, the altitude can be defined as a region where the altitude is almost the same in a wide area such as a flat land, and the data amount of data stored in the altitude storage unit is reduced.

  A fourth invention is the positioning circuit according to any one of the first to third inventions, wherein the altitude storage unit allows each region to be specified in a rectangular shape by allowing overlapping between the specified regions. The area specifying information is associated with the altitude of the area and stored so as to be searchable in descending order of altitude priority, and the positioning unit stores the area including the approximate position in the altitude storage unit. It is a positioning circuit that searches from the highest in order of priority.

  The eleventh aspect of the invention is the positioning method of the ninth or tenth aspect of the invention, wherein each of the areas is specified in a rectangular shape in the altitude storage unit while allowing overlapping between the specified areas. The area specifying information is stored in association with the altitude of the area so as to be searchable in descending order of priority of the altitude, and the positioning step includes the area in which the area including the approximate position is stored in the altitude storage unit. It is a positioning method that is a step of searching from the highest in order of priority of altitude.

  According to the fourth or eleventh aspect of the invention, the altitude storage unit stores the area specifying information in which each area is specified in a rectangular shape while allowing overlap between specified areas, and corresponds to the altitude of the area. In addition, it is stored so as to be searchable in descending order of priority of altitude, and the area including the approximate position is searched from the areas stored in the altitude storage unit in the order of high altitude. In other words, since overlapping between regions where altitude is defined is allowed, for example, in the case of terrain where the altitude changes such as a hill, different altitudes from the lowest altitude to the highest altitude of this hill are associated. It can be set to stack multiple regions. In this case, when searching, since the search is performed in order from the defined high altitude priority area, the altitude corresponding to the approximate position is correctly searched. Thereby, a reduction in the amount of data stored in the altitude storage unit is realized as compared with the case where the overlap between regions is not allowed.

  5th invention is the positioning circuit of 3rd or 4th invention, Comprising: The said altitude memory | storage part has memorize | stored hierarchically the area block containing a some area, and the area contained in the said area block The positioning unit is a positioning circuit that searches for a region block including the approximate position and then searches each region included in the region block.

  According to the fifth invention, the altitude storage unit hierarchically stores the area block including a plurality of areas and the area included in the area block, and searches for the area block including the approximate position, Next, each area included in the area block is searched. Thereby, the efficiency of the search of the area including the approximate position is improved.

  A sixth invention is the positioning circuit according to any one of the first to fifth inventions, wherein the positioning unit includes the altitude of the current position measured and the area where the altitude is stored in the altitude storage unit. It is a positioning circuit that compares the altitude corresponding to the area including the current position and determines the altitude of the current position.

  The twelfth invention is the positioning method according to any of the ninth to eleventh inventions, wherein the positioning step includes the altitude of the current position measured and the altitude stored in the altitude storage unit. This is a positioning method that is a step of determining the altitude of the current position by comparing with the altitude corresponding to the area including the current position.

  According to the sixth or twelfth invention, the altitude at the current position is determined by comparing the altitude at the current position measured with the altitude corresponding to the area including the current position stored in the altitude storage unit. . Thereby, the accuracy of the current position measured is confirmed. That is, if the compared altitudes match, it can be determined that the measured current position is almost accurate. On the other hand, if they do not match, it can be determined that the degree of accuracy is low. In this case, the altitude of the current position may be determined, for example, as the altitude of the current position measured, or the altitude storage unit You may change the altitude stored in

  A seventh invention is the positioning circuit according to any one of the first to sixth inventions, wherein the positioning unit previously searched for an area stored in the altitude storage unit or the altitude undefined area storage unit If the search position is the same as the current search position, the current search position is not used for the current search position, and the current search position altitude is used as the previous search position.

  A thirteenth invention is the positioning method according to any of the ninth to twelfth inventions, wherein the positioning step searches the area stored in the altitude storage unit or the altitude undefined area storage unit last time. If the search position at this time is the same as the current search position, this is a positioning method that is a step of setting the current search position altitude as the previous search altitude without performing the current search.

  According to the seventh or thirteenth invention, when the search position when the area stored in the altitude storage unit or the no altitude area storage unit is searched last time is the same as the current search position, The altitude at the current search position without searching is the altitude at the previous search. In other words, when the search position is the same, the search altitude is the same, and therefore there is no need to perform a search. This improves the efficiency of advanced searches. However, in this case, it is necessary to store the previous search position and the altitude at the time of the previous search.

  An eighth invention is an electronic apparatus including the positioning circuit according to any one of the first to seventh inventions.

  According to the eighth aspect of the invention, an electronic device having the effects of any one of the first to seventh aspects of the invention is realized.

  The fourteenth invention is a program for causing a computer to execute the positioning method of any of the ninth to thirteenth inventions.

  According to the fourteenth aspect, the same effect as any one of the ninth to thirteenth aspects can be achieved by causing the computer to execute arithmetic processing according to the program.

  Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings. In the following, a mobile phone that is an electronic device including a positioning circuit will be described, but embodiments to which the present invention can be applied are not limited thereto.

[Mobile phone]
The mobile phone 1 according to the present embodiment has a call function as a telephone and has a built-in positioning circuit. The navigation is such that the current position of the mobile phone 1 measured by the positioning circuit is plotted on a map and displayed on a display. It has a function. The positioning circuit calculates the current position by performing arithmetic processing based on GPS satellite signals received from a plurality (4 or more) of GPS satellites.

  FIG. 1 is a block diagram showing an internal configuration of the mobile phone 1. According to FIG. 1, the mobile phone 1 includes a GPS antenna 10, a GPS receiving unit 20 that is a positioning circuit, a host CPU (Central Processing Unit) 41, an operation unit 42, a display unit 43, and a ROM (Read Only). Memory) 44 and RAM (Random Access Memory) 45.

  The GPS antenna 10 is an antenna that receives an RF signal including a GPS satellite signal transmitted from a GPS satellite, and outputs the received RF signal.

  The GPS receiving unit 20 captures and extracts a GPS satellite signal from the RF signal received by the GPS antenna 10, and performs a positioning calculation based on a navigation message or the like extracted from the GPS satellite signal to calculate a current position. The GPS receiver 20 includes a SAW (Surface Acoustic Wave) filter 21, an LNA (Low Noise Amplifier) 22, an RF (Radio Frequency) receiver 23, a TCXO (Temperature Controlled Crystal Oscillators) 24, and baseband processing. Circuit portion 30. In the GPS receiving unit 20, the RF receiving circuit unit 23 and the baseband processing circuit unit 30 can be manufactured as separate LSIs (Large Scale Integration) or as a single chip. . Further, the entire GPS receiving unit 20 including the SAW filter 21, the LNA 22, and the TCXO 24 can be manufactured as one chip.

  The SAW filter 21 is a band-pass filter, passes a signal in a predetermined band with respect to the RF signal input from the GPS antenna 10, and blocks and outputs a frequency component outside the band. The LNA 22 is a low noise amplifier, and amplifies the signal input from the SAW filter 21 and outputs the amplified signal. The TCXO 24 is a temperature compensated crystal oscillator, and generates and outputs an oscillation signal having a predetermined oscillation frequency. The RF receiving circuit unit 23 multiplies (synthesizes) the signal input from the LNA 22 with a signal obtained by dividing or multiplying the oscillation signal input from the TCXO 24 and converts the signal into an intermediate frequency signal (IF signal). After the IF signal is amplified, it is converted into a digital signal by A / D conversion and output.

[Baseband processing circuit section]
The baseband processing circuit unit 30 captures and tracks a GPS satellite signal from the IF signal input from the RF receiving circuit unit 23, decodes the data, and based on the navigation message, time information, etc. It is a circuit part which performs calculation calculation of this, positioning calculation, etc.

  Specifically, the GPS satellite signal is first captured based on the input IF signal. The acquisition of the GPS satellite signal is a process of extracting the GPS satellite signal from the IF signal, and performs a correlation process on the IF signal. Specifically, a coherent process for calculating the correlation between the IF signal and the pseudo-generated replica C / A code (code replica) using an FFT operation is performed, and a correlation value as a result of the coherent process is calculated. Incoherent processing is performed to calculate a correlation integrated value by integration. Thereby, the phase of the C / A code and the carrier frequency included in the GPS satellite signal is obtained.

  If the GPS satellite signal is acquired, then the acquired GPS satellite signal is tracked. GPS signal tracking is a process of performing synchronization holding of a plurality of captured GPS satellite signals in parallel. For example, a cold loop that is realized by a delay lock loop (DLL) and tracks the phase of a C / A code, for example, A carrier loop that is implemented by a phase lock loop (PLL) and tracks the phase of the carrier frequency is performed. Then, the tracked GPS satellite signal data is decoded to extract a navigation message, and a pseudo-range calculation, a positioning calculation, and the like are performed to determine the current position.

  The baseband processing circuit unit 30 includes a CPU 31, a ROM 32, and a RAM 33, and includes various circuits such as a replica C / A code generation circuit, a correlation calculation circuit, and a data decoding circuit.

  The CPU 31 comprehensively controls each unit of the baseband processing circuit unit 30 and each unit of the RF reception circuit unit 23 and performs various arithmetic processes including a baseband process described later.

  In the baseband processing, the CPU 31 extracts a GPS satellite signal from the IF signal input from the RF receiving circuit unit 23 and decodes the navigation message. Then, based on the orbit information and time information of each GPS satellite included in the decoded navigation message, the pseudo distance with each captured GPS satellite is calculated, and the current position is calculated by performing a positioning operation based on the calculated pseudo distance. To do.

  As positioning calculation, first, three-dimensional positioning calculation is performed. If the three-dimensional positioning is successful, the calculated positioning position is output to the host CPU 41 at the subsequent stage as the current position of the mobile phone 1. On the other hand, when the 3D positioning fails, for example, due to poor reception of radio waves, an altitude table search process is performed to search for altitudes with reference to the altitude table stored in the ROM 32, and based on the retrieved altitudes. Two-dimensional positioning calculation is performed to calculate latitude and longitude. Then, the calculated positioning position is output to the host CPU 41 at the subsequent stage as the current position of the mobile phone 1. In the present embodiment, the position obtained by the positioning calculation is expressed by latitude, longitude, and altitude, but may be expressed by, for example, a three-dimensional coordinate value in the earth reference coordinate system. .

[Advanced table]
The altitude table is a data table in which a plurality of areas on which the altitude on the earth is to be defined is defined and the altitude is defined in each area. Here, there are various types of altitude, such as an ellipsoidal height, an altitude above sea level, and an altitude. There are two types of altitude tables. That is, for example, an altitude table defining a specific altitude such as “100 m” and a non-altitude table defining no altitude.

  FIG. 2 is a diagram for explaining the outline of the altitude table. FIG. 2A shows a plan view of a part of terrain in Japan, and FIG. 2B shows a cross-sectional view taken along the line AA ′ in FIG. This partial terrain is formed with a hill on the left side and a plain that is an urban area on the right side. Here, the altitude of the flatland is almost “0 m”, and the altitude of the hill gradually increases toward the left side. And as shown in FIG. 3, the area 50 used as the application range of an altitude table is set to this topography. The region 50 has a rectangular shape, and each side of the rectangle is set in a direction along the latitude direction or the longitude direction. Further, the length of each side of the region 50 is arbitrary, that is, the size of the region 50 is arbitrary.

  For the altitude table, a region 50 is set so as to include a point that approximates the reference altitude, with a predetermined altitude determined at predetermined intervals as a reference. In the altitude table applied to each area 50, this reference altitude is defined as the altitude of the area 50. For example, in FIG. 3, the region 50 is set with “100 m” as the reference height interval and “0 m”, “100 m”, and “200 m” as the reference height.

  Specifically, a region 50A having a reference altitude of “0 m” is set. That is, the region 50A is set so as to include a point where the altitude is close to “0 m” which is the reference altitude, specifically, a point where the altitude is “50 m” or less. In FIG. 3, the area 50 </ b> A is set so as to include the flat land on the right side of the topography. An altitude table having an altitude of “0 m” is applied to the area 50A. However, the area 50A may include points with an altitude of “50 m” or higher, and priority is given to setting all the points that approximate the reference altitude “0 m”.

  In FIG. 3, one area 50A having a reference altitude of “0 m” is set. However, in the case where places close to the reference altitude are discrete like stepping stones, each of these areas is included. A plurality of regions 50A may be set as described above.

  Next, an area 50B having a reference altitude of “100 m” is set. That is, the region 50B is set so as to include points where the altitude is close to the reference altitude “100 m”, specifically, points where the altitude is “50 m” or more and “150 m” or less. In FIG. 3, three regions 50 </ b> B are set so as to include the skirt portion on the flat land side of the hill. An altitude table having an altitude of “100 m” is applied to the area 50B. However, the area 50B may overlap with the area 50A having the previously set reference altitude of “0 m”. Further, the area 50B may include points with an altitude of “150 m” or higher, and priority is given to setting so as to include all points that approximate the reference altitude “100 m”.

  Subsequently, a region 50C having a reference altitude of “200 m” is set. That is, the region 50C is set so as to include a point where the altitude is close to the reference altitude “200 m”, specifically, a point where the altitude is “150 m” or more and “250 m” or less. In FIG. 3, two regions 50C are set so as to include the top of the hill. An altitude table having an altitude of “200 m” is applied to the area 50C. However, the region 50C may overlap with the region 50A having the reference altitude set to “0 m” and the region 50B having the reference altitude “100 m”, and includes all points that approximate the reference altitude “200 m”. Setting to is prioritized.

  In addition, among the tables with altitude, a priority order for determining a search order to be described later is set between tables where the applied regions 50 overlap. Specifically, the priority order is determined according to the order in which the specified altitude is higher. In other words, in FIG. 3, the priority order of the altitude “200 m” table applied to the region 50C is the highest, followed by the “100 m” altitude table applied to the region 50B, and then applied to the region 50A. It becomes the order of the table with altitude of altitude “0 m” to be performed.

  On the other hand, the table without altitude is applied to an area in which the table with altitude is applied and it is determined that the altitude is not defined. Specifically, for example, it is set in a relatively narrow range and a large change in altitude. In FIG. 3, two regions 50Z are set in each of the two regions 50A to which the table with an altitude of “0 m” is applied. Then, a no altitude table in which the altitude is set to “no definition” is applied to the region 50Z.

  By the way, the altitude table (the table with altitude and the table without altitude) is set to a place where the navigation function can be used, that is, a place where a person exists or enters. For example, an urban area, a residential area, an area within a certain distance from a road, and the like. In addition, the altitude table is not set in a place where it is determined that a person usually does not enter. For example, in the mountains without roads, on the sea, etc., in FIG. 3, the left part of the hill with a high altitude is regarded as a place where people cannot enter, and no altitude table is set. Then, there is a possibility that the navigation function is used, but a table without altitude is set in a specific place. For example, hilly areas in urban areas.

  Furthermore, each altitude table of the table with altitude and the table without altitude is classified hierarchically for each area block, with the area block including the area 50 to which it is applied being the upper hierarchy.

  FIG. 4 is a diagram illustrating an example of a regional block. As shown in FIG. 4, the regional block 60 is a range obtained by dividing Japan, which is the entire terrain, by local units such as Hokkaido, Tohoku region, and Kanto region, and is defined as several to dozens. The area block 60 is a rectangular range, and each side of the rectangle is defined along the latitude direction or the longitude direction. Further, the length of each side of the rectangle is arbitrary, that is, the size of the regional block 60 is arbitrary. Further, the regional blocks 60 are determined so that the regional blocks 60 do not overlap each other. Further, the area block 60 is determined so that all the altitude tables are always included in any area block 60.

  In the altitude table search process, the CPU 31 sets the latitude and longitude calculated by the previous positioning calculation (two-dimensional positioning or three-dimensional positioning) as a search position that is a position (schematic position) that roughly indicates the current position, and the ROM 32. Referring to the block data group 121, the regional block including the search position is searched.

  FIG. 5 is a diagram illustrating an example of the data configuration of the block data group 121. As shown in FIG. 5, the block data group 121 includes a plurality of block data 122 that are data for each of the regional blocks 60. Each block data 122 is continuously stored in a predetermined storage area of the ROM 32. Note that the storage order of the block data 122 is not particularly limited. In FIG. 5, the respective block data 122 are stored in the order of the regional blocks A, B,... From the top of the storage area.

  These block data 122 are all the same size (data size), and the latitude and longitude of the center of the corresponding regional block 60, the length of 1/2 of the length in the latitude direction, and the length in the longitude direction. Of the table with no altitude belonging to the area block, and the head position and the end position of the table with altitude.

  The “head position and end position of the table without altitude” are, as will be described later, the storage position (head position) and the end of the head table among the tables without altitude 126 continuously stored in the ROM 32, respectively. It is a value (for example, address) indicating the storage position (end position) of the tail table. Further, “the head position and the end position of the table with altitude” are the storage positions (head positions) of the head table among the tables with altitude 124 continuously stored in the ROM 32, as will be described later. And a value (for example, address) indicating the storage position (end position) of the last table. Further, as shown in FIG. 6, the “region block center” is the center O of the rectangle, and the “length in the longitude direction and the latitude direction” is the length of each side of the rectangle. This definition is the same for the region 50 to which the altitude table is applied.

  That is, the CPU 31 targets the block data 122 included in the block data group 121 in order from the top in the storage order, and determines whether or not the corresponding regional block 60 includes a search position. If it is determined that the search position is included, the search of the block data group 121 is terminated at that time, and it is determined that the search position is included in the regional block 60 corresponding to the block data 122 determined to be included. When there is no area block 60 including the search position, the search altitude is set to “no definition”.

  Next, with reference to the no altitude table group 125 of the ROM 32, it is determined whether or not the search position is included in the area to which the no altitude table 126 belonging to the determined area block 60 is applied.

  FIG. 7A is a diagram illustrating an example of a data configuration of the no altitude table group 125. As shown in FIG. 7A, the non-altitude table group 125 includes a plurality of non-altitude tables 126. Each table without altitude 126 is continuously stored in a predetermined storage area of the ROM 32. Specifically, all the altitudeless tables 126 belonging to the same regional block 60 are stored so as to be continuous. In FIG. 7A, the no altitude table 126 belonging to each regional block 60 is continuously stored in the order of regional blocks A, B,... From the top of the storage region. Note that there is no restriction on the storage order of the non-altitude tables 126 belonging to the same regional block 60.

  These altitude-less tables 126 are all the same size (data size), and the latitude and longitude of the center of the area to be applied, half the length in the longitude direction, and the length in the latitude direction. Of half the length. Then, as shown in FIG. 7B, in the no altitude table 126 belonging to the same regional block 60, the storage position of the first table in the storage order is the start position, and the storage position of the last table is the end position. Is stored in the block data 122 of the regional block.

  The CPU 31 uses the table without altitude 126 included in the determined area block 60 as a determination target in the order of storage, and determines whether or not the search position is included in the area 50 to which the table without altitude 126 is applied. If it is determined that the search position is included, the search of the no altitude table group 125 is terminated at that time, and the search position is set to “no definition”. On the other hand, if all of the no-altitude table 126 included in the determined area block 60 is searched, but there is no area 50 including the search position, then the determined area is determined by referring to the table 32 with altitude in the ROM 32. Of the tables with altitude belonging to the block 60, a table applied to the region 50 including the search position is determined.

  FIG. 8A is a diagram illustrating an example of the data configuration of the table table 123 with altitude. As shown in FIG. 8A, the altitude table group 123 includes a plurality of altitude tables 124. Each altitude presence table 124 is continuously stored in a predetermined storage area of the ROM 32. Specifically, as with the no altitude table group 125, all the altitude tables 124 belonging to the same regional block 60 are stored so as to be continuous. In FIG. 8A, the altitude presence table 124 belonging to each regional block 60 is stored in order of the regional blocks A, B,.

  The altitude presence table 124 belonging to the same regional block 60 is stored in the order according to the determined priority order. As described above, this priority order is based on the altitude defined in each altitude table 124. Specifically, the priority order increases in descending order of the defined altitude table. It should be noted that for the table with altitude 124 belonging to the same regional block 60 and having the same defined altitude, a priority order corresponding to the applied region 50 is further determined and stored in accordance with this priority order. May be. For example, even in an altitude table 124 in which the same altitude “500 m” is defined, the table applied to the urban area has a higher priority in the urban area and the mountain area, so Store and be retrieved first.

  The tables with altitude 124 are all the same size (data size), and the latitude and longitude of the center of the area 50 to be applied, the length of half the length in the latitude direction, and the longitude direction Includes half the length and altitude. Then, as shown in FIG. 8B, among the tables with altitude 124 belonging to the same regional block 60, the storage position of the first table in the storage order is set as the start position, and the storage position of the last table is set as the end position. Is stored in the block data 122 of the regional block 60.

  The CPU 31 sets the altitude presence table 124 included in the determined area block 60 as a determination target in the order of storage, and determines whether or not the search position is included in the area 50 to which the altitude presence table 124 is applied. If it is determined that the search position is included, the search of the table with altitude 123 is terminated at that time, and the altitude defined by the table with altitude 124 determined to be included is set as the search altitude. On the other hand, when all the altitude tables 124 included in the determined area block 60 are searched, but there is no area 50 including the search position, the search altitude is set to “no definition”.

  Returning to FIG. 1, the ROM 32 stores a system program for the CPU 31 to comprehensively control the baseband processing circuit unit 30 and programs and data for executing various processes including the baseband process.

  FIG. 9 is a diagram illustrating an example of the configuration of the ROM 32. As shown in FIG. 9, the ROM 32 stores a baseband processing program 110, a block data group 121, an altitude table group 123, and an altitude table group 125.

  The RAM 33 is used as a work area of the CPU 31, and temporarily stores programs and data read from the ROM 32, data input from the RF receiving circuit unit 23, calculation results executed by the CPU 31 according to various programs, and the like.

  FIG. 10 is a diagram illustrating an example of the configuration of the RAM 33. As shown in FIG. 10, the RAM 33 stores search position data 211, search altitude data 213, and positioning data 215.

  The search position data 211 is search position data that is a current approximate position that is searched in the altitude table search process. FIG. 11 is a diagram illustrating an example of a data configuration of the search position data 211. According to FIG. 11, the search position data 211 stores the current (latest) and previous (previous) search positions. The search position data 211 is updated every time the altitude table search process is performed by the CPU 31.

  The search altitude data 213 is data of altitude (search altitude) searched by the altitude table search process. FIG. 12 is a diagram illustrating an example of a data configuration of the search altitude data 213. As illustrated in FIG. The search altitude data 213 is updated every time the altitude table search process is performed by the CPU 31.

  The positioning data 215 is position data obtained by positioning calculation (three-dimensional positioning or two-dimensional positioning). FIG. 13 is a diagram illustrating an example of a data configuration of the positioning data 215. According to FIG. 13, the positioning data 215 stores latitude, longitude, and altitude. This positioning data is updated each time a positioning calculation (three-dimensional positioning or two-dimensional positioning) is performed by the CPU 31.

  Returning to FIG. 1, the host CPU 41 comprehensively controls each unit of the mobile phone 1 according to various programs such as a system program stored in the ROM 44. Specifically, the telephone function as a telephone is mainly realized, and a navigation screen in which the current position of the mobile phone 1 input from the baseband processing circuit unit 30 is plotted on a map is displayed on the display unit 43. Processing for realizing various functions including a navigation function is performed.

  The operation unit 42 is an input device configured by operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by a user to the host CPU 41. The display unit 43 is a display device configured by an LCD (Liquid Crystal Display) or the like, and displays a display screen based on a display signal input from the host CPU 41.

  The ROM 44 stores a system program for the host CPU 41 to control the mobile phone 1 in an integrated manner, and application programs and data for realizing various functions including a navigation function. The RAM 45 is used as a work area of the host CPU 41, and temporarily stores programs and data read from the ROM 44, operation data input from the operation unit 42, calculation results executed by the host CPU 41 according to various programs, and the like.

  The portable radio communication unit 46 is a known communication circuit unit realized by an antenna, an RF conversion circuit, or the like that transmits and receives radio signals to and from a radio base station installed by a cellular phone communication service provider. Radio signals are transmitted and received based on the control of the CPU 41.

[Process flow]
FIG. 14 is a flowchart for explaining the flow of the baseband processing. This processing is realized by the CPU 31 performing processing according to the baseband processing program 110.

  According to FIG. 14, the CPU 31 first determines a GPS satellite capable of receiving a GPS satellite signal based on the orbit information of a GPS satellite such as an almanac and adds a new GPS satellite to be captured, A capture target satellite determination process is performed such that a GPS satellite that is considered to be in a possible position is excluded from the capture target (step A1).

  Next, satellite information including the position, velocity, and moving direction of each GPS satellite to be captured is calculated based on the navigation message decoded from the input IF signal (step A3). Then, a three-dimensional positioning process based on the calculated satellite information is performed to calculate the current position (step A5). The calculated current position is stored in the positioning data 215.

  If the three-dimensional positioning is successful (step A7: YES), the positioning data 215 is output to the host CPU 41 (step A21). On the other hand, if the three-dimensional positioning fails (step A7: NO), such as when the number of captured GPS satellites is three or less, the altitude table search process is subsequently performed (step A9).

  When the altitude table search process ends, it is determined whether or not there is a value of the searched altitude (search altitude). The search altitude is stored in the search altitude data 213. If the search altitude is "no definition" (step A11: NO), it is determined that positioning cannot be performed, and "positioning failure" is output to the host CPU 41 as a positioning result (step A23). On the other hand, if there is a search altitude (step A11: YES), then a two-dimensional positioning process based on the search altitude is performed (step A13). The current position (latitude and longitude) calculated by the two-dimensional positioning process is stored in the positioning data 215 together with the search altitude. Next, altitude table search processing is performed (step A15).

  When the altitude table search process ends, it is determined whether or not the search altitude stored in the search altitude data 213 matches the altitude of the positioning data 215. If they match (step A17: YES), the positioning data 215 is determined. Is output to the host CPU 41 (step A21). On the other hand, if the search altitude does not match the altitude of the positioning data 215 (step A21: NO), after changing the altitude of the positioning data 215 to the search altitude (step A19), the positioning data 215 is output to the host CPU 41 ( Step A21).

  Thereafter, the CPU 31 determines whether or not to end positioning. That is, for example, when a positioning end instruction is input from the host CPU 41 due to an instruction operation for turning the navigation function “OFF” or an instruction operation for turning the power source “OFF”, the positioning is ended. to decide. If the positioning is not finished (step A25: NO), the process returns to step A1, and if the positioning is finished (step A25: YES), this process is finished.

  FIG. 15 is a flowchart for explaining the flow of the altitude table search process. According to FIG. 15, first, the search position data 211 is updated with “current search position” as “previous search position” and positioning position as “current search position” (step B1). Next, a match between the current search position and the previous search position is determined. If they match (step B3: YES), the search altitude is not changed. That is, the previous search altitude is used as it is as the current search altitude (step B21).

  On the other hand, if the current search position does not match the previous search position (step B3: NO), the block data group 121 is referenced to search the area block 60 including the current search position (step B5). If there is no regional block 60 including the current search position (step B7: NO), the search altitude data 213 is updated with the search altitude set to “no definition” (step B19).

  On the other hand, if there is an area block including the current search position (step B7: YES), then, with reference to the no altitude table group 125, it is set in the no altitude table 126 belonging to the area block 60. The table in which the area where the current location includes the current search position is searched (step B9). As a result of the search, if the no altitude table 126 in which the set region includes the current search position is found (step B11: YES), the search altitude data 213 is updated with the search altitude set to “no definition” (step B11: YES). Step B19).

  On the other hand, if the table without altitude 126 is not found (step B11: NO), referring to the table with altitude 123, the set area of the table with altitude 124 belonging to the area block 60 is determined. A table including the current search position is searched (step B13). If, as a result of the search, an altitude table 124 in which the set region includes the current search position is found (step B15: YES), the altitude defined in the altitude table 124 is retrieved as the search altitude. The altitude data 213 is updated (step B17). On the other hand, if the altitude presence table 124 is not found (step B15: NO), the search altitude data 213 is updated with the search altitude as “no definition” (step B19). When the above process is performed, the altitude table search process is terminated.

[Action / Effect]
As described above, according to the present embodiment, the positioning calculation based on the GPS satellite signal is first performed by three-dimensional positioning. If 3D positioning fails due to a small number of GPS satellites captured due to problems such as reception environment (3 or less), 2D positioning based on altitude obtained by searching a preset altitude table will be performed. Done. The altitude table is a data table in which altitudes are defined for each of a plurality of preset regions, and there are an altitude table in which an altitude such as “100 m” is defined and a table without altitude in which no altitude is defined. The area where the altitude table is set has a rectangular shape whose size can be arbitrarily set, and is allowed to overlap with other areas. Thereby, reduction of the data amount of the whole altitude table is realized.

  In addition, setting an undefined table avoids errors during two-dimensional positioning and improves the reliability of the current position after positioning. That is, for example, when an altitude table is set for a place where the altitude changes greatly in a relatively narrow range, it is necessary to divide the place into a number of ranges corresponding to the altitude and to define the altitude for each. In addition, when these altitude tables are searched, since the divided range is narrow, the difference between the search position and the actual position is likely to occur. As a result, the altitude of the range specified as the range including the search position is increased. The actual altitude will be different, and the error of the current position for two-dimensional positioning will increase. However, as in this embodiment, by not defining the altitude for such a place (a place where the altitude change is large in a relatively narrow range), an error caused by a shift between the search position and the actual position is avoided. Therefore, it is possible to improve the reliability of the current position measured. Furthermore, by not defining the altitude, it is possible to reduce the data amount of the entire altitude table.

[Modification]
It should be noted that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

(A) Host CPU
For example, part or all of the processing performed by the CPU 31 of the baseband processing circuit unit 30 may be performed by the host CPU 41 in software.

(B) Electronic Device In the above-described embodiment, the case where the present invention is applied to a mobile phone as an electronic device including a positioning circuit has been described. However, other electronic devices such as PDA (Personal Digital Assistants) and portable navigation are used. It is equally applicable to other electronic devices such as devices and car navigation devices.

(C) Satellite Positioning System In the above-described embodiment, the case where GPS is used has been described, but it is needless to say that the present invention can be similarly applied to other satellite positioning systems such as GLONASS (GLObal NAvigation Satellite System).

(D) Recording medium The band-band processing program 110 may be recorded on a recording medium such as a CD-ROM and installed in an electronic device having the GPS receiver 20.

The internal structure of the mobile phone of the embodiment. An example of topography. Example of regional settings where altitude data is applied. Setting example of regional block. The data block diagram of a block data group. Region definition. The data block diagram of a table group without altitude. The data block diagram of a table group with altitude. The block diagram of ROM. The block diagram of RAM. The data block diagram of search position data. The data structure figure of search altitude data. The data block diagram of positioning data. The flowchart of a baseband process. The flowchart of the altitude table search process performed during a baseband process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Portable telephone, 10 GPS antenna, 20 GPS receiving part, 30 Baseband processing circuit part, 31 CPU, 32 ROM, 33 RAM, 41 Host CPU, 46 Portable radio | wireless communication part

Claims (14)

An altitude storage unit for storing the altitude of each region;
An area without altitude definition for storing an area in which the altitude is not defined in any of the areas;
It is determined whether or not the given approximate position is in the area stored in the area storage unit without altitude definition, and if it is in the stored area, the two-dimensional current position using the altitude is not measured. If not within the stored area, based on the altitude corresponding to the area including the approximate position of the areas where the altitude is stored in the altitude storage unit, the approximate position, and the satellite signal from the positioning satellite A positioning unit that measures the current position;
Positioning circuit equipped with. The altitude storage unit stores the altitude of the area where the altitude on the earth should be stored,
The positioning unit does not measure the two-dimensional current position using the altitude when the approximate position is not in any area where the altitude is stored in the altitude storage unit.
The positioning circuit according to claim 1.   The positioning circuit according to claim 1 or 2, wherein the altitude storage unit stores area specifying information for specifying each area divided in a rectangular shape in association with an altitude of the area. The altitude storage unit can search for region specifying information in which each region is specified in a rectangular shape by allowing overlapping between specified regions in association with the altitude of the region in descending order of priority of the altitude. Remember
The positioning unit searches an area including the approximate position from an area stored in the altitude storage unit in descending order of altitude priority.
The positioning circuit as described in any one of Claims 1-3. The altitude storage unit hierarchically stores a region block including a plurality of regions and regions included in the region block,
The positioning unit searches for an area block including the approximate position, and then searches for each area included in the area block.
The positioning circuit according to claim 3 or 4.   The positioning unit determines the altitude of the current position by comparing the altitude of the current position measured with the altitude corresponding to the area including the current position among the areas where the altitude is stored in the altitude storage unit. Item 6. The positioning circuit according to any one of Items 1 to 5.   The positioning unit does not perform the current search when the search position at the time of the previous search for the area stored in the altitude storage unit or the altitude undefined area storage unit is the same as the current search position. The positioning circuit according to any one of claims 1 to 6, wherein the altitude at the current search position is the altitude at the time of the previous search.   The electronic device which comprised the positioning circuit as described in any one of Claims 1-7. A given approximate position is stored in an altitude undefined area storage unit that stores an area in any one of the above-mentioned each area of the altitude storage unit in which the altitude of each area is stored and in which the altitude is not defined. A determination step for determining whether or not the area is within a certain area;
As a result of the determination, if the area is stored in the area storage unit without altitude definition, the two-dimensional current position is not measured using the altitude, and if it is not within the stored area, the altitude memory is stored. A positioning step of positioning the current position based on the altitude corresponding to the area including the approximate position of the area where the altitude is stored in the unit, and the approximate position and the satellite signal from the positioning satellite;
Positioning method including. The altitude storage unit stores the altitude of the area where the altitude on the earth should be stored,
The positioning step is a step of not measuring the two-dimensional current position using the altitude when the approximate position is not in any area where the altitude is stored in the altitude storage unit.
The positioning method according to claim 9. In the altitude storage unit, region specifying information in which each region is specified in a rectangular shape while allowing overlap between specified regions is searched in association with the altitude of the region in descending order of priority. Is remembered as possible,
The positioning step is a step of searching for the area including the approximate position from the areas stored in the altitude storage unit in the descending order of altitude priority.
The positioning method according to claim 9 or 10.   The positioning step includes a step of determining the altitude of the current position by comparing the altitude of the current position measured with the altitude corresponding to the area including the current position among the areas where the altitude is stored in the altitude storage unit. The positioning method according to any one of claims 9 to 11.   The positioning step does not perform the current search when the search position when the previous search of the area stored in the altitude storage unit or the altitude undefined area storage unit is the same as the current search position. The positioning method according to any one of claims 9 to 12, which is a step of setting the altitude of the current search position as the altitude when the previous search is performed.   The program for making a computer perform the positioning method as described in any one of Claims 9-13.

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