JP2015127674A - GPS smart system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GPS smart system in which when a GPS signal is receivable, a main coordinate positioned on the basis of the GPS signal remains preliminarily synchronized with a sub coordinate positioned without relying on the GPS signal and when the GPS signal is hard or impossible to be received, a coordinate pertain to a current location is configured to be displayed on an electronic map on the basis of the sub coordinate.SOLUTION: A GPS smart system 10 is adapted to connect a main unit 11 composed of a portable terminal device and the like and a sub unit 12 different in a unit from the main unit with a radio communication line 13. The sub unit is configured to; regularly position the main coordinate on the basis of the GPS signal; superimpose the sub coordinate formed in the same cycle as that of the main coordinate and not relying on the GPS on the main coordinate; when the GPS signal cannot be received, dispose the sub coordinate having a distance and an azimuth identified by a velocity pulse and electronic compass at a scheduled position where the main coordinate is supposed to be disposed; and display the sub coordinate in an electronic map on a monitor 24 in association of the sub coordinate with the electronic map.

Description

  The present invention relates to a navigation system used for a vehicle, a ship, an aircraft, or a similar mobile object using a smart phone, a mobile phone, a tablet terminal device, or a similar mobile terminal device having a global positioning system (GPS) function. It is related with the GPS smart system which comprised.

  In recent years, smart phones, mobile phones, tablet-type terminal devices, or similar mobile terminal devices have a GPS function for receiving GPS signals emitted from global positioning system (hereinafter referred to as “GPS”) satellites and measuring their positions. doing. The GPS function of the portable terminal device has a simple configuration as compared with a conventional car navigation system, but is a function sufficient to know the current position. Therefore, it is used as a portable navigation device (PND) that can be carried instead of expensive car navigation.

On the other hand, various functions can be added to mobile terminal devices, particularly smartphones and tablet-type terminal devices, by installing application software as well as calling functions.
Here, the car audio system by wireless communication transmission of utility model registration No. 3179256 is provided with a smartphone connected to the in-vehicle car audio system via a wireless communication line, and the GPS mounted on the smartphone and the monitor screen of the smartphone are used. A car navigation system is disclosed.

Utility Model Registration No. 3179256

However, it is very difficult for a car navigation system to receive a GPS signal in a place where radio waves are blocked or diffusely reflected, for example, in a tunnel or behind a building. Moreover, the accuracy of the unencrypted GPS signal transmitted from the GPS satellite is intentionally lowered. As a result, in the supplement of the current position that relies only on the GPS satellite, an error occurs between the coordinates measured based on the GPS signal and the coordinates related to the map displayed on the screen. Therefore, the conventional car navigation system is equipped with an auxiliary device such as a gyroscope or a vehicle speed sensor to supplement the positioning means by the GPS satellite, or corrects the current position from the difference between the mark whose coordinates are known and the measured coordinates. As described above, error correction means for periodically correcting an error between the coordinates on the map and the coordinates relating to the actual current position is provided.
And also about the GPS function mounted in portable terminal devices, such as a smart phone, it has an error correction means which corrects the above errors. However, since the portable terminal device has a limited number of parts for weight reduction, the error correction means does not incorporate a device such as a gyro or add a device such as a vehicle speed sensor. An actual current position is estimated by receiving a plurality of radio signals other than GPS signals transmitted from a plurality of radio stations such as a mobile phone base station or a wireless LAN spot whose coordinates on the map are known. For this reason, for example, in places where there are few mobile phone base stations, such as highways running in mountainous areas, valleys of high-rise buildings, and places where wireless LAN spots are not established, the actual current position can be measured accurately. It becomes very difficult to correct the position based on the radio signal.

  Therefore, the problem to be solved by the present invention is that when the GPS signal is receivable, the main coordinate measured based on the GPS signal and the sub-coordinate measured without using the GPS signal are synchronized in advance. Another object of the present invention is to provide a GPS smart system that displays a coordinate on an electronic map on the electronic map based on the sub-coordinate when the GPS signal is difficult to receive or cannot be received.

The GPS smart system according to claim 1 is a main storage medium in which an electronic map based on online map information data provided via the Internet is recorded in a readable manner,
A display unit having a monitor for displaying the electronic map;
A main control unit that controls scrolling and enlargement / reduction display of the electronic map, and controls display of the electronic map so that predetermined coordinates on the electronic map are located at the center of the monitor;
And a main communication unit having a bidirectional communication means having a main wireless unit that communicates with the slave wireless unit bidirectionally via a wireless communication line,
A main unit comprising a smartphone, a mobile phone, a tablet-type terminal device or a similar mobile terminal device, and
A bi-directional communication means having a slave radio section that communicates with the main radio section bidirectionally via the radio communication line; and a sub-communication section having a GPS receiving means having a GPS antenna for receiving a GPS signal;
Positioning means for positioning the main coordinates based on the GPS signal, and sub-coordinate forming means for forming sub-coordinates arranged at substantially the same positions as the positions of the main coordinates that are periodically formed. A sub-control unit that controls to arrange the sub-coordinates at a position synchronized with the main coordinates, with respect to the position of the main coordinates periodically formed based on
And a sub-storage medium for recording the coordinate data relating to the main coordinates and the sub-coordinates in a readable manner,
A subunit having
When the GPS signal can be received,
In the subunit, positioning the main coordinates and forming the sub coordinates arranged in synchronization with the main coordinates,
When the GPS signal is difficult to receive or cannot be received,
In the subunit, the sub-coordinate is formed so as to overlap the coordinate where the main coordinate is to be arranged when a GPS signal can be received,
Coordinate data related to the main coordinate or the sub-coordinate is transmitted from the subunit to the main unit via the wireless communication line,
Regardless of the reception state of the GPS signal, the main unit displays the main coordinate or the sub-coordinate based on the coordinate data superimposed on the corresponding predetermined coordinate on the electronic map. And

The GPS smart system according to claim 2 is the invention according to claim 1, wherein the sub-coordinate forming means is
Sub-coordinate arrangement means for periodically arranging the sub-coordinates at substantially the same position as the main coordinates;
Among the plurality of arranged sub-coordinates, the latest two sub-coordinates are used as the reference coordinates, the subsequent sub-coordinates are used as updated coordinates, and the plurality of arranged sub-coordinates are identified. Sub-coordinate identifying means for assigning a code;
Distance measuring means for measuring a distance between the reference coordinates and the updated coordinates;
Azimuth measuring means for measuring the direction of the updated coordinates viewed from the reference coordinates,
When the sub-coordinate is arranged and adjacent to the sub-coordinate and the other sub-coordinate are the reference coordinate and the update coordinate,
The position of the update coordinate is determined based on the relative distance and direction of the update coordinate with respect to the reference coordinate.

The GPS smart system according to claim 3 is the invention according to claim 2, wherein the distance measuring means includes
A speed pulse detecting means for detecting a speed pulse periodically emitted from a vehicle, a ship, an aircraft, or a moving body similar to these,
The number of the speed pulses detected by the speed pulse detecting means between one main coordinate and the other main coordinate is counted, and a reference between the reference coordinates and the update coordinates synchronized with both the main coordinates Providing a reference speed setting means for setting the speed,
When the GPS signal is receivable,
Measuring a distance between one main coordinate and another main coordinate based on the GPS signal, and setting a reference distance between the reference coordinate and the update coordinate;
By dividing the reference distance by the number of speed pulses counted by the reference speed setting means, a reference speed consisting of a moving distance per pulse is set,
When the GPS signal is difficult to receive or cannot be received,
The distance between the adjacent sub-coordinates periodically arranged by the sub-coordinate arranging means is
Calculate from the reference speed and the number of speed pulses counted between one sub-coordinate and the other sub-coordinate,
The distance between one adjacent sub-coordinate and the other sub-coordinate is measured.

  According to a fourth aspect of the present invention, in the GPS smart system according to the second aspect, the direction measuring unit includes a geomagnetic sensor that detects geomagnetism, and measures the direction based on the geomagnetism detected by the geomagnetic sensor. It is an electronic compass.

According to the GPS smart system of claim 1, the mobile terminal device capable of displaying an electronic map based on online map information data provided via the Internet is a main unit, and is received from a GPS satellite separately from the main unit. A subunit for positioning the main coordinates based on the GPS signal is provided. When the sub-unit is capable of receiving GPS signals, it transmits coordinate data related to the main coordinates to the main unit and arranges the sub-coordinates so as to overlap the position of the main coordinates, making it difficult to receive GPS signals. Alternatively, when the GPS signal cannot be received, coordinate data related to the sub-coordinates arranged at the position where the main coordinates are arranged is transmitted to the main unit when the GPS signal is receivable.
In addition, a GPS antenna is provided in the subunit so that GPS signals can be received. Therefore, it is possible to use a larger and more sensitive antenna than the GPS antenna included in the mobile terminal device of the main unit.
As a result, when the GPS signal can be received, the main coordinates measured based on the GPS signal and the sub-coordinates that can be measured without using the GPS signal are synchronized in advance, and the GPS signal is difficult to receive or When reception becomes impossible, the coordinates relating to the current position can be displayed on the electronic map based on the coordinate data relating to the sub-coordinates.

According to the GPS smart system according to claim 2, the sub-coordinate forming unit forms an adjacent reference coordinate and an update coordinate, and the position of the update coordinate from the relative distance and direction of the update coordinate with respect to the reference coordinate. I decided to decide. When the coordinate correction means according to claim 1 synchronizes the positions of the two adjacent main coordinates measured based on the GPS signal, the reference coordinates, and the update coordinates, and the GPS signal cannot be received. Can be prepared for.
As a result, when the GPS signal can be received, the main coordinates measured based on the GPS signal and the sub-coordinates that can be measured without using the GPS signal are synchronized in advance, and the GPS signal is difficult to receive or When reception becomes impossible, the coordinates relating to the current position can be displayed on the electronic map based on the coordinate data relating to the sub-coordinates.

According to the GPS smart system of the third aspect, the distance measuring unit preliminarily calculates a reference distance between the reference coordinates and the update coordinates and a reference speed that is a moving distance per one pulse of the speed pulse from the reference distance. It can be prepared and prepared in case the GPS signal cannot be received.
As a result, when the GPS signal can be received, the main coordinates measured based on the GPS signal and the sub-coordinates that can be measured without using the GPS signal are synchronized in advance, and the GPS signal is difficult to receive or When it becomes impossible to receive, the distance between the sub-coordinates can be obtained from the reference speed and the number of speed pulses, so the coordinates related to the current position are displayed on the electronic map based on the coordinate data related to the sub-coordinates. Can do.

According to the GPS smart system of the fourth aspect, the azimuth measuring means measures the direction of the updated coordinate with respect to the reference coordinate with an electronic compass having a geomagnetic sensor. Therefore, it is possible to specify the position of the update coordinate disposed on any one of the spherical surfaces having the reference coordinate and the center as the radius with the reference distance as a center. By cooperating with the distance measuring means, the height difference between the reference coordinates and the updated coordinates can be determined, and a change in distance reflecting the height difference can be added to the reference distance.
As a result, when the GPS signal is difficult to receive or cannot be received, the coordinates related to the current position based on the coordinate data related to the sub-coordinates displayed on the electronic map can be obtained with high accuracy.

1 is a system diagram showing an outline of a configuration of a GPS smart system according to a first embodiment. It is explanatory drawing which shows the example of attachment of the GPS smart system which concerns on 1st Example. It is a block diagram which shows the outline of a structure of the GPS smart system which concerns on 1st Example. It is explanatory drawing explaining the distance measuring method of the GPS smart system which concerns on 1st Example. It is explanatory drawing explaining the direction correction method of the GPS smart system which concerns on 1st Example. It is a system diagram which shows the example which added the other apparatus to the GPS smart system which concerns on 1st Example. It is a flowchart figure explaining the positioning method of the GPS smart system which concerns on 1st Example.

An embodiment of a GPS smart system according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an outline of the configuration of the GPS smart system according to the present embodiment, and FIG. 2 shows an outline of an example of mounting the GPS smart system. Moreover, FIG. 3 is a block diagram which shows the outline of a structure of the GPS smart system based on a present Example.

As shown in FIG. 1, the GPS smart system 10 includes a main unit 11 and a subunit 12, and the main unit 11 and the subunit 12 are connected to each other via a wireless communication line 13.
In this embodiment, the communication standard related to the wireless communication line 13 is based on Bluetooth (registered trademark). In addition, it is not limited to the said standard, You may employ | adopt another communication standard.
The main unit 11 includes a smartphone, a mobile phone, a tablet terminal device, or a mobile terminal device similar to these. As shown in FIG. 2, the main unit 11 is fixed to the vehicle body via an attachment member 3 made of a cradle, a bracket, or the like attached on the dashboard 2 of the vehicle 1. Since the wireless communication line 13 is employed, the installation location of the main unit 11 can be determined without worrying about wiring work. The installation location can be placed near the meter, for example, to reduce the movement of the driver's line of sight. In particular, as shown in FIG. 2, the monitor surface is directed toward the driver on the dashboard so that it can be easily seen by the driver. You may make it do.
As shown in FIG. 2, the sub unit 12 is disposed near the main unit 11 such as a floor surface under a seat or a glove box, and is fixed to the vehicle body. In this way, by installing the subunit 12 in an inconspicuous place under the seat or behind the dashboard, a housing that accommodates the subunit 12 is, for example, one that can be manufactured in large quantities at low cost without considering design. You may do it. This can reduce the manufacturing cost.
In this embodiment, the GPS smart system 10 has been applied to an automobile, but is not limited to this. For example, the GPS smart system 10 may be applied to a mobile body such as a bicycle, a motorcycle, a ship or an airplane.

As shown in FIG. 3, the main unit 11 includes a main storage medium 20, a display unit 21, a main control unit 22, and a main communication unit 23.
The main storage medium 20 is a storage medium capable of recording a large amount of data such as a hard disk drive (HDD), a solid state drive (SSD), or a flash medium, and is formed so that data can be freely recorded and read. The main storage medium 20 stores online map information data provided via the Internet, and based on this, the main unit 11 can display an electronic map. The online map information data is appropriately updated via the Internet so as to be kept up-to-date. The online map information data includes at least coordinates including latitude and longitude in addition to the topographic map. Thus, by designating coordinates, an arbitrary area centered on the coordinates can be displayed on a monitor described later.

  The display unit 21 has a monitor 24. The monitor 24 is formed so that at least an electronic map can be displayed. The monitor 24 includes a touch panel, and is configured such that when the electronic map is displayed on the monitor 24, the electronic map is scrolled in any direction when the finger is slid on the monitor 24. Furthermore, the electronic map is displayed in an enlarged or reduced display when a finger movement or a screen is tapped. As a result, the user can view the electronic map at an arbitrary magnification.

The main control unit 22 includes a main control unit 25 that controls display related to the electronic map, and a first positioning unit 26 that preferably measures coordinates based on a GPS signal.
The main control means 25 is configured to control scrolling for moving the electronic map in the vertical and horizontal directions, and to control zooming in / out of the electronic map. Further, when predetermined coordinates are input to the main unit 11, the coordinates and the electronic map are controlled so that the predetermined coordinates are located at the center of the monitor 24. By displaying the predetermined coordinates as the center in this way, it is possible to realize a GPS function of displaying an electronic map around the coordinates measured by the first positioning means 26 based on the GPS signal. Also, a navigation function is provided by scrolling the electronic map so that coordinates that are updated one after another are positioned at the center of the monitor 24 while inputting a route in advance and determining whether or not the coordinates are moving according to the route. Can be realized. Further, even when the GPS function or the navigation function is not used, it can be used, for example, for examining a route from a station or landmark building to a destination.

  The 1st positioning means 26 is formed so that the coordinate on the earth may be located based on the GPS signal emitted from the several GPS satellite. The coordinates consist of at least latitude and longitude, and preferably may include altitude. And the 1st positioning means 26 is formed so that the coordinate data based on the measured coordinate may be produced | generated. The coordinate data includes at least information related to coordinates (latitude, longitude, altitude), and preferably includes various information such as domestic standard time based on the standard time used by GPS satellites to synchronize with each other. It is.

  The coordinate data formed by the first positioning means 26 is formed so as to be recorded and saved in the main storage medium 20 by the main control means 25. Thereby, for example, by reading the coordinate data with another terminal device such as a personal computer, the travel route can be reproduced on the electronic map of the other terminal device.

The main communication unit 23 includes a bidirectional communication unit 27 and a GPS reception unit 29, and is configured to transmit and receive signals related to communication of the main unit 11.
The bidirectional communication means 27 includes a main wireless unit 28 and is configured to perform bidirectional communication with each other via a wireless communication line 13 with a slave wireless unit 45 provided in a subunit 12 described later. .
The GPS receiving means 29 has a main GPS antenna 30 and is configured to receive GPS signals emitted from a plurality of GPS satellites. By the cooperation of the GPS receiving unit 29 and the first positioning unit 26, the main unit 11 can determine the distance to each of a plurality of GPS satellites and determine the coordinates relating to the current position.

As shown in FIG. 3, the sub unit 12 includes a sub communication unit 40, a sub control unit 41, a sub storage medium 42, and a power source 43.
Similar to the main storage medium 20, the sub storage medium 42 is a storage medium capable of recording a large amount of data such as a hard disk drive (HDD), a solid state drive (SSD), or a flash medium, and can record data freely. It is formed to be readable.
The power supply 46 has a power input terminal 43a and a ground terminal 43b. The power input terminal 43a is connected to an output terminal of the accessory power supply so that power is input from the accessory power supply of the vehicle. As a result, it is possible to drive without worrying about running out of the battery as compared with the case where the power supply of the subunit is taken from the dry battery. The ground terminal 43b is grounded to the vehicle. Thereby, a short circuit accident can be prevented.

The sub-communication unit 40 includes a bidirectional communication unit 44 and a GPS reception unit 46, and is configured to transmit and receive signals related to the communication of the subunit 12.
The bidirectional communication means 44 has a slave radio unit 45. The slave radio unit 45 is configured to communicate bidirectionally with the main radio unit 28 via the radio communication line 13. Thereby, the subunit 12 can exchange various data with the main unit 11.
The GPS receiving means 46 has a sub GPS antenna 47. The sub GPS antenna 47 is formed to receive GPS signals emitted from a plurality of GPS satellites. The GPS receiving unit 46 is configured to output the received GPS signal to the second positioning unit 48 of the sub-control unit 41.
The sub GPS antenna 47 is attached to a predetermined position of the vehicle, for example, on the dashboard shown in FIG. 2 or on the roof or in the trunk. Since the sub GPS antenna 47 can be fixed to the vehicle, the size and shape can be freely designed. Thereby, compared with the main GPS antenna 30 of the main unit 11 which consists of a portable terminal device, it can be set as a larger and highly sensitive antenna. Thereby, a weaker GPS signal than that received by the main GPS antenna 30 can be received.
Therefore, in the present embodiment, the coordinates are determined based on the GPS signal received by the sub GPS antenna 47.
However, the present invention is not limited to this. If the main GPS antenna 30 of the main unit 11 can receive a sufficiently strong GPS signal, the main unit 11 may measure the coordinates. In addition, the main GPS antenna 30 and the sub GPS antenna 47 are switched to be used so that the signals received more clearly among the GPS signals received by the main GPS antenna 30 and the sub GPS antenna 47 are used. Also good.

  The sub control unit 41 has second positioning means 48 and sub coordinate forming means 49. The sub-control unit 41 is configured to perform control for adjusting the position of the sub-coordinate measured by the sub-coordinate forming unit 49 according to the main coordinate measured by the second positioning unit 48.

The second positioning means 48 is formed so as to periodically measure the main coordinates based on the reception period of the received GPS signal. The main coordinate is composed of at least latitude and longitude, and preferably may include altitude. And the 2nd positioning means 48 is formed so that the coordinate data concerning a main coordinate may be produced | generated. The coordinate data includes at least information related to the main coordinates (latitude, longitude, altitude), and preferably includes various information such as domestic standard time based on the standard time used by GPS satellites to synchronize with each other. include. Coordinate data relating to the main coordinates is recorded in the sub storage medium 42.
In the present embodiment, the period for positioning the main coordinates is set to 1 second intervals or 0.1 second intervals. The said period is not limited to these, It can set at arbitrary intervals.

The sub-coordinate forming unit 49 includes a sub-coordinate arranging unit 55, a sub-coordinate identifying unit 56, a distance measuring unit 57, and an azimuth measuring unit 58, which are substantially the same so as to overlap with the periodically formed main coordinates. The sub-coordinate is formed at the position.
The sub-coordinate arrangement means 55 arranges the sub-coordinates superimposed on the main coordinates based on the coordinate data relating to the main coordinates at the same cycle as the main coordinates periodically formed by the second positioning means 48. Is formed. Thereby, the same number of sub-coordinates as the main coordinates are arranged. The position of the arranged sub-coordinate is specified by the following sub-coordinate identifying means 56, distance measuring means 57, and azimuth measuring means 58.

The sub-coordinate identifying means 56 is formed so as to define the latest sub-coordinate as the reference coordinate and the adjacent sub-coordinate as the updated coordinate for the latest two sub-coordinates among the plurality of arranged sub-coordinates. Has been. As a result, the position of the updated coordinate that is scheduled to be superimposed with the main coordinate of the latest cycle is adjusted with respect to the reference coordinate that is already superimposed with the main coordinate by the processing of the previous cycle for the periodically formed main coordinate. Only the main coordinates and the sub-coordinates can be superimposed one after another. The sub-coordinate identifying means 56 is formed so as to give an identification code to the arranged sub-coordinates in order. The identification code is not particularly limited, but may be a number or a code. Thereby, even if it is a case where a some subcoordinate is formed, the formed order can be grasped | ascertained easily. Therefore, it is possible to record the coordinate data related to the sub-coordinates in the sub storage medium 42 and use the coordinate data like a so-called GPS logger.
Adjustment of the position of the update coordinate with respect to the reference coordinate is performed by the following distance measuring means 57 and azimuth measuring means 58.

  The distance measuring means 57 includes a speed pulse detecting means 60 and a reference speed setting means 61, and measures the reference distance between the reference coordinates and the update coordinates, and also measures the reference speed between the reference coordinates and the update coordinates. Is formed.

  The speed pulse detection means 60 has a vehicle speed signal input terminal 60a. The vehicle speed signal input terminal 60a is formed so that a vehicle speed signal is input from the vehicle body side. The vehicle speed signal is a signal indicating the speed of the vehicle, and represents a change in speed depending on the number of pulse signals included per unit time. The pulse signal is referred to as a speed pulse in this embodiment. If the number of speed pulses included per unit time is large, it is determined that the vehicle speed is fast, and if it is small, the vehicle speed is slow.

  The reference speed setting means 61 is configured to set a reference speed for a reference distance between the reference coordinates and the update coordinates. The reference speed setting means 61 counts the number of speed pulses detected by the speed pulse detection means 60, and the reference is determined based on the number of speed pulses and the reference distance between the reference coordinates and the update coordinates, that is, the GPS signal. The reference speed between the reference coordinates and the update coordinates is measured from the distance between the main coordinates corresponding to the coordinates and the main coordinates corresponding to the update coordinates.

The reference speed is measured as described below. As shown in FIG. 4, the sub-coordinate arrangement unit 55 and the sub-coordinate identification unit 56 form A, B, C, and D sub-coordinates. Here, when the sub-coordinate A is the reference coordinate, the sub-coordinate B is the updated coordinate. As the distance between A and B, a distance of 16.5 m between the main coordinates actually measured by the second positioning means 48 is obtained. When the reference speed setting means 61 counts the number of speed pulses between A and B and it is 55 counts, the moving distance per pulse is 0.3 m / count. This speed is set as a reference speed between A and B, and reference speed data relating to the reference speed is recorded in the sub storage medium 42.
When the next measurement cycle starts, the sub-coordinate B becomes the reference coordinate and the sub-coordinate C becomes the update coordinate. Similarly, when the distance between B and C is 19 m and 56 counts, a reference speed of 0.34 m / count is obtained and similarly recorded in the sub storage medium 42. At this time, in this embodiment, it is formed so as to overwrite the reference speed data of the previous period, but an average may be taken from the reference speeds of a plurality of periods.
Then, after positioning the sub-coordinate C, when the main coordinate corresponding to the sub-coordinate D is not positioned, if the reference speed setting means 61 counts 57 speed pulses between CD, the previous reference speed data is obtained. When read from the sub storage medium 42 and multiplied, the position of the sub-coordinate D with respect to the sub-coordinate C can be estimated at 0.34 m / count × 57 = 19.38 m.

  In this embodiment, the reference speed setting means 61 always updates and records the reference speed data for each of the reference speed between A and B and between the reference speed between B and C and the sub-coordinates. By this, while the GPS signal can be received, measure the distance between the sub-coordinates from the distance between the main coordinates measured based on the GPS signal, and prepare for when the GPS signal cannot be received. Can do. Then, when the second positioning means 48 cannot receive the GPS signal, the distance of the subsequent sub-coordinate can be determined based on the reference speed related to the latest reference speed data recorded in the sub storage medium 42. . Thereby, even if it is a case where a main coordinate cannot be measured, a GPS function is realizable by a subcoordinate.

The azimuth measuring means 58 includes an electronic compass 65. The electronic compass 65 has a geomagnetic sensor 66 that detects geomagnetism. The electronic compass 65 is formed so as to measure the direction based on the geomagnetism detected by the geomagnetic sensor 66.
The geomagnetic sensor 66 is a triaxial sensor that detects geomagnetism centering on an axis extending along the north-south direction, an axis extending along the east-west direction, and an axis extending along the top-and-bottom direction. Thereby, the electronic compass 65 is also formed so as to detect the azimuth in the vertical direction in addition to the east, west, south, and north directions. Thereby, in addition to the heading in the traveling direction, the altitude difference between the reference coordinate and the updated coordinate can be determined from the inclination in the vertical direction. Then, the actual distance of the updated coordinates relative to the reference coordinates can be determined more accurately from the altitude difference and the movement distance between the reference coordinates measured by the distance measuring means 61 and the updated coordinates.
As shown in FIG. 2, the geomagnetic sensor 66 is preferably attached to a place where the outside of the vehicle can be seen well, for example, in the vicinity of the rearview mirror. This is to remove as much as possible the influence of the iron plate used in the vehicle body, magnetized parts such as speakers of the in-vehicle audio system, and the engine.
Further, when the GPS signal can be received, the azimuth measuring unit 58 detects the one main coordinate based on the GPS signal, the azimuth obtained from the other main coordinates adjacent to the main coordinate, and the geomagnetic sensor 66. It is formed so as to periodically correct the azimuth error determined from the reference coordinates and the updated coordinates. Thereby, even if the direction detected by the geomagnetic sensor 66 is out of order due to the influence of strong magnetism, it can be promptly corrected to the correct direction and restarted.

The azimuth correction is performed as described below. As shown in FIG. 5, sub-coordinates A, B, C, and D are formed by the sub-coordinate placement unit 55 and the sub-coordinate identification unit 56. Here, when the sub-coordinate A is the reference coordinate, the sub-coordinate B is the updated coordinate. Further, hereinafter, the azimuth angle is assumed to make a round in the clockwise direction with 0 degree as the north.
The azimuth of the sub-coordinate B with respect to the sub-coordinate A is the azimuth of another main coordinate with respect to one main coordinate measured by the second positioning means 48, and is set to 100 °. When the azimuth measuring means 58 measured the azimuth of the sub-coordinate B with respect to the sub-coordinate A, it was 102 °. In this case, the azimuth by the geomagnetic sensor from the actually measured value 100 ° based on the GPS signal, and −2 ° by subtracting 102 ° are recorded in the sub storage medium 42 as the azimuth correction data for correcting the deviation of the geomagnetic sensor.
When the next measurement cycle starts, the sub-coordinate B becomes the reference coordinate and the sub-coordinate C becomes the update coordinate. Similarly, when the orientation of another principal coordinate with respect to one principal coordinate is 130 ° and the orientation of the subsidiary coordinate C with respect to the subsidiary coordinate B is 127 °, orientation correction data of 3 ° is obtained. Are recorded in the sub storage medium 42. At this time, in the present embodiment, the azimuth correction data of the previous cycle is overwritten, but an average may be taken from the azimuth correction data of a plurality of cycles.
Then, after positioning the sub-coordinate C, when the main coordinate corresponding to the sub-coordinate D is not measured, and the orientation of the sub-coordinate D with respect to the sub-coordinate C is 160 °, the previous azimuth correction data is sub-stored. When read from the medium 42 and added, the orientation of the sub-coordinate D with respect to the sub-coordinate C can be corrected at 160 ° + 3 ° = 163 °.

  As described above, the azimuth measuring unit 58 can detect the azimuth error of the updated main coordinate with respect to the reference coordinate indicated by the geomagnetic sensor 66 while the GPS signal can be received. Is formed so as to periodically correct. As a result, it is possible to periodically correct the deviation of the geomagnetic sensor that is likely to be distorted by a speaker, an iron plate, or an electric device in the vehicle. Then, the corrected azimuth correction data is recorded in the sub storage medium 42 so that it can be read out instantaneously, so that the azimuth correction data is obtained in the azimuth obtained from the geomagnetic sensor even when the GPS signal is interrupted. By applying, it is possible to obtain a bearing with high accuracy.

When the positional relationship between the reference coordinates measured by the distance measuring means 57 and the azimuth measuring means 58 and the next updated coordinates is centered on the reference coordinates, the updated coordinates are based on the reference distance measured by the distance measuring means 57 as a radius. And is determined at one point on the spherical surface according to the direction measured by the azimuth measuring means 58.
As a result, even if the GPS signal is difficult to receive or cannot be received, the reference coordinates and the updated coordinates can be measured without depending on the GPS signal, and consequently, the transition of a plurality of sub-coordinates formed periodically is determined. By doing so, the GPS function can be executed. Then, by recording the sub-coordinate transition in the sub storage medium 42, it can be used like a GPS logger.
In the present embodiment, the azimuth measuring means 58 detects the azimuth and inclination by the triaxial geomagnetic sensor 66. However, the present invention is not limited to this, and the azimuth is measured by a gyro instead of the geomagnetic sensor 66. It is also possible to detect the difference in altitude using an altimeter or a barometer.

Further, the subunit 12 may include a signal input / output unit 70 having input / output terminals for transmitting and receiving a plurality of types of signals. For example, as shown in FIG. 4, the signal input / output unit 70 preferably includes an audio signal output terminal 80 related to an audio signal, an audio signal input terminal 81, and an infrared signal input terminal 82.
The audio signal output terminal 80 is connected to the car audio device and is configured to output audio from the speaker 80a. Thereby, for example, the voice related to the voice navigation transmitted from the main unit 11 via the wireless communication line 13 can be output from the speaker 80a.
The audio signal input terminal 81 is formed to connect a microphone 81a and input audio. Thereby, for example, the operation command of the main unit 11 or the subunit 12 can be input by voice using the microphone 81a or the hands-free operation can be performed using the telephone function of the main unit 11 including the mobile terminal device via the wireless communication line 13. You can talk on the phone.
The infrared signal input terminal 82 has an infrared light receiving sensor 82a, and is configured to be able to receive an operation signal obtained by electrically converting an optical signal by infrared rays transmitted from a remote controller 82b. Thereby, the car audio device and the main unit 11 can be remotely operated by the remote control 82b. The main unit 11 uses portable terminal devices in this embodiment. That is, by installing application software in the main unit 11, various functions can be added in addition to the telephone and GPS. Therefore, the operation keys of the remote controller 82b may be associated with the operation commands of the application software so that the added various functions are remotely operated by the remote controller 82b.

  The above is the configuration of the GPS smart system 10 according to the present embodiment. Next, the operation of the GPS smart system 10 will be described with reference to the attached drawings. FIG. 5 is a flowchart showing the operation of the GPS smart system 10 according to the present embodiment.

  Step S100 is a step of performing a process of starting the GPS smart system 10 by turning on the accessory power supply of the automobile. This activates the subunit that is powered from the accessory power supply.

  Step S105 is a step of performing processing for automatically connecting the main unit 11 and the subunit 12 via the wireless communication line 13. Thereby, the coordinate data concerning the main coordinate or the sub-coordinate can be transmitted from the subunit 12 to the main unit by the bidirectional communication means. The transmitted coordinate data is reflected on the electronic map by the main control unit 22 of the main unit 11, and the position on the electronic map corresponding to the coordinates included in the coordinate data is arranged at the center of the monitor 24. Be controlled. As a result, the GPS function can be realized by the main unit 11 based on the coordinate data obtained by the subunit 12. When the pairing between the main unit 11 and the subunit 12 is authenticated on the wireless communication line 13 and the process of connecting to each other is completed, the process proceeds to step S110.

Step S110 is a step of performing processing for starting the speed pulse detecting means. As a result, the speed pulse detection means 60 detects the speed pulse input from the vehicle speed signal input terminal 60a, and the reference speed setting means 61 counts the number of the speed pulses at a predetermined interval, and the movement distance per pulse. The process which sets the reference speed which is is performed.
In this embodiment, the predetermined interval is set to 1 second or 0.1 second interval. Thereby, the number of speed pulses detected by the speed pulse detecting means 60 and counted by the reference speed setting means 61 is collected every 1 second or every 0.1 seconds. Alternatively, the average number of moving distances per pulse may be measured by sampling the number of velocity pulses counted periodically over a predetermined time.
When the speed pulse detector 60 starts counting the speed pulses, the process proceeds to the next step S115.

  Step S115 is a step in which the electronic compass 65 included in the azimuth measuring means 58 performs processing for detecting the azimuth. The electronic compass 65 performs processing for detecting geomagnetism by the geomagnetic sensor 66 and determining the direction. At this time, a process of correcting the error of the electronic compass 65 by comparing the predetermined azimuth measured by the electronic compass 65 and the predetermined azimuth measured based on the GPS signal is also performed. Thereby, for example, it is possible to correctly determine the azimuth by eliminating the influence of magnetism on the iron plate of the vehicle body and the magnet of the speaker of the car audio device. After the electronic compass 65 is activated, the process proceeds to the next step S120.

In step S120, the sub-GPS antenna 47 receives GPS signals from a plurality of GPS satellites, and performs a process of confirming the reception state based on the GPS signals to determine whether the second positioning means 48 can measure the main coordinates. Step to perform. After confirming the reception state, the reception state is determined in step S125.
In this embodiment, the positioning is performed by the second positioning means 48. However, the present invention is not limited to this, and coordinate data transmitted from the first positioning means 26 of the main unit 11 may be used. In this step, the average value of the coordinate data related to the respective main coordinates measured by the first positioning means 26 and the second positioning means 48 may be taken.

Step S125 is a step of performing a process of determining whether or not a GPS signal has been received.
This process measures the reception sensitivity of the radio wave related to the GPS signal actually received by the sub GPS antenna 47, and if it exceeds a predetermined threshold, it can be received, and if it is less than the threshold, it is difficult to receive, Alternatively, a process for determining that reception is impossible is performed. Further, the main GPS antenna 30 may be used in place of the sub GPS antenna 47 for determination of the reception sensitivity.
Here, the main coordinates measured based on the GPS signal include at least latitude and longitude, and are formed by positioning based on GPS signals received from at least three GPS satellites. When the altitude is included in the main coordinates, it is required to receive GPS signals from at least four GPS satellites. Therefore, it is possible to determine that it is difficult to receive a GPS signal when the reception sensitivity of at least one of the GPS signals necessary for positioning the main coordinates is weak.
If the GPS signal can be received, the process proceeds to step S130. If the GPS signal cannot be received or is difficult to receive, the process proceeds to step S170.

In steps S130 to S160, when the GPS signal can be received, one main coordinate is obtained from the main coordinate based on the GPS signal and the sub-coordinate formed by the sub-coordinate forming unit 49 so as to be synchronized with the main coordinate. Based on the process of measuring the distance between one sub-coordinate and another sub-coordinate with respect to the distance of the other main coordinate adjacent to the one main coordinate with a speed pulse, and the direction of the other main coordinate with respect to the one main coordinate This is a step of performing a process of measuring the azimuth of another sub-coordinate with respect to one sub-coordinate measured by the geomagnetic sensor 66 and correcting the deviation of the azimuth by the geomagnetic sensor 66.
Step S130 is a step of performing processing for reading out the coordinate data related to the immediately preceding main coordinate from the sub storage medium 42. Hereinafter, the immediately preceding main coordinate measured based on the GPS signal is set as the first coordinate, and the sub-coordinate formed in synchronization with the first coordinate is set as the reference coordinate.

  Step S135 is a step in which the second positioning means 48 performs a process of positioning the main coordinates based on the GPS signal received in step 125. The main coordinates measured here are hereinafter referred to as second coordinates. At this time, the sub-coordinate arrangement unit 55 arranges the sub-coordinate at a position overlapping with the second coordinate in synchronization with the second coordinate. The sub coordinates are set as update coordinates by the sub coordinate identifying means 56. After positioning the second coordinates and forming the updated coordinates, the process proceeds to the next step S140.

  Step S140 is a step of performing a process of setting a reference speed between the first coordinate and the second coordinate (reference coordinate and update coordinate). Dividing the distance between the first coordinate and the second coordinate that the vehicle has moved by the number of pulses of the speed pulse detected in step S110 can determine the movement distance per pulse, and the movement distance per pulse can be determined as the reference coordinate. And speed data relating to the reference speed between the updated coordinates. After measuring the speed data, the process proceeds to the next step S145.

  Step S145 is a step of performing processing for recording the speed data in the sub storage medium 42. At this time, the speed data obtained in the processing step of the previous cycle may be overwritten, or the average value of the reference speed may be taken together with the speed data accumulated up to the previous cycle. The speed data is read in step S170 when the GPS signal cannot be received as a result of the determination process in step S125 and the process proceeds to step S170, or the first coordinate is obtained in step S130 of the next cycle. When read out, it is read out and used at the same time in order to use the reference speed in the first coordinate.

Step S150 is a step of performing processing for correcting the orientation based on the electronic compass 65 by the orientation based on the GPS signal.
First, the azimuth of the second coordinate relative to the first coordinate is measured from the first coordinate read from the sub storage medium 42 and the second coordinate measured by the second positioning means 48 in step S135, and preferably the altitude difference is determined. Perform the process of determining. On the other hand, the azimuth measuring means 58 measures the azimuth of the updated coordinates with respect to the reference coordinates by the electronic compass 65, and preferably performs a process of determining the altitude difference.
Then, based on the azimuth of the second coordinate with respect to the first coordinate, a process for correcting the deviation of the azimuth of the updated coordinate with respect to the reference coordinate indicated by the electronic compass is performed, that is, the deviation of the azimuth indicated by the electronic compass 65 is corrected. Processing is performed. The data relating to the correction azimuth is hereinafter referred to as azimuth correction data. When this process ends, the process proceeds to the next step S155.

  Step S155 is a step of performing processing for recording the azimuth correction data in the sub storage medium 42. Through the processing from step S130 to step S155, the second coordinates measured based on the GPS signal and the updated coordinates formed by the sub-coordinate forming unit 49 so as to be synchronized with the second coordinates are overlapped, The speed data related to the reference speed associated with the coordinate data related to the two coordinates (updated coordinates) and the azimuth correction data related to the deviation of the electronic compass 65 are prepared so as to be readable. Then, the process proceeds to step S160.

Step S160 is a step of performing processing for recording the coordinate data relating to the second coordinate and the updated coordinate in the sub storage medium 42. Coordinate data related to the updated coordinates is recorded in association with the coordinate data related to the second coordinates, and speed data and azimuth correction data are recorded in association with the coordinate data related to the updated coordinates.
As a result, the second coordinate of the previous cycle can be read as the first coordinate in step S130 of the next cycle, and the reference coordinate that was the updated coordinate in the previous cycle is associated with the first coordinate. When the GPS signal is difficult to receive or cannot be received, the speed data and the azimuth correction data associated with the reference coordinates can be quickly read out.

Step S165 is a step of performing processing for transmitting coordinate data related to the second coordinate (updated coordinate) from the subunit 12 to the main unit 11 via the wireless communication line 13. The coordinate data is associated with the speed data and the azimuth correction data formed in the above processing step, but only the coordinate data related to the second coordinate (updated coordinate) is transmitted in this step. It is preferable.
Thereby, the main unit 11 which received coordinate data performs control which reflects the 2nd coordinate contained in coordinate data on the coordinate on an electronic map. As a result, the current position related to the second coordinates is displayed on the displayed electronic map on the monitor 24.
And after performing the process of step S130 to step S165, it returns to step S110 and the same process is performed with a predetermined period. In this embodiment, the period is performed every second or every 0.1 seconds, but is not limited to this. For example, the correction process is performed once every plural periods of receiving the GPS signal. Can be set arbitrarily.

  If it is determined in step S125 that the GPS signal cannot be received satisfactorily, the process proceeds to step S170. A series of processes in that case will be described below.

  Step S170 is a step of performing a process of reading coordinate data related to the first coordinates from the sub storage medium 42. Since the position of the first coordinate included in the coordinate data related to the first coordinate is also the position of the reference coordinate, even if it is difficult or impossible to receive the GPS signal, the position of the reference coordinate is used as a reference. The position of the update coordinate can be specified. After the coordinate data related to the first coordinate is prepared, the process proceeds to the next step S175.

  Step S175 is a step of performing a process of reading speed data related to the reference speed associated with the coordinate data when the coordinate data related to the first coordinate is read. Then, when the process ends, the process proceeds to the next step S180.

  Step S180 is a step of performing processing for determining the distance between the reference coordinates and the updated coordinates. In this step S180, the second positioning means 48 performs processing for setting the next sub-coordinate adjacent to the reference coordinate at the same period as the period in which the main coordinate is located, and the sub-coordinate is set as the sub-coordinate. The identification means 56 performs processing for setting the updated coordinates. Then, the speed pulse detection means 60 detects and counts the number of speed pulses between the reference coordinates and the update coordinates, and the distance measurement means 57 counts the reference speed that is the movement distance per pulse in the read reference coordinates. A process for measuring the reference distance between the reference coordinates and the update coordinates is performed by multiplying the number of speed pulses. The distance data related to the reference distance is temporarily recorded in the sub storage medium 42.

  Step S185 is a step of performing processing for reading out the azimuth correction data associated with the coordinate data when the coordinate data related to the first coordinate is read out. From the read out azimuth correction data, a process of determining the deviation between the traveling direction in the reference coordinates and the electronic compass 65 is performed, and the process proceeds to the next step S190.

  Step S190 is a step of performing processing for determining the direction of the updated coordinates with respect to the reference coordinates. In this step, a process of measuring the azimuth of the update coordinate with respect to the reference coordinate including the correction angle by reflecting the read out azimuth correction data on the azimuth of the update coordinate with respect to the reference coordinate measured by the electronic compass 65 of the azimuth measuring means 58. Do. Preferably, the altitude difference between the reference coordinate and the updated coordinate is obtained based on the inclination of the electronic compass 65 in the vertical direction, and the angle formed by the straight line connecting the reference coordinate and the updated coordinate in the east, west, south, and north directions is determined. May be. Direction data relating to the direction and angle of the updated coordinates with respect to the reference coordinates is temporarily recorded in the sub storage medium 42.

Step S195 is a step of performing processing for specifying the position of the updated coordinate with respect to the reference coordinate based on the distance data and the direction data. As for the positional relationship between the reference coordinates and the update coordinates, first, it is required that the update coordinates exist on the surface of the sphere with the reference coordinates as the center and the reference distance as the radius based on the distance data. By reflecting the direction and angle included in the direction data here, the position of the updated coordinate with respect to the reference coordinate can be specified. The position of the specified update coordinate is recorded as coordinate data related to the update coordinate in the sub storage medium 42 in step S160, and the coordinate data is transferred from the subunit 12 to the main unit 11 by the bidirectional communication means in step S165. Sent.
Thereby, the main unit 11 that has received the coordinate data performs control to reflect the updated coordinates included in the coordinate data on the coordinates on the electronic map. As a result, the current position related to the updated coordinates is displayed on the displayed electronic map on the monitor 24.

  By performing the processing from step S170 to step S195 in this way, even if the GPS signal is difficult to receive or cannot be received, the position of the updated coordinate with respect to the reference coordinate calculated based on the speed data and the direction correction data is obtained. Based on the distance data and the direction data, the position of the updated coordinate can be calculated, and the coordinate of the sub-coordinate arranged at the point where the main coordinate is to be arranged can be specified. Therefore, the current position related to the main coordinate or the sub-coordinate can be displayed on the electronic map of the main unit 11 regardless of the reception state of the GPS signal.

According to the GPS smart system 10 according to the present embodiment, in the area where the GPS signal from the GPS satellite can be received, the sub coordinate is arranged so as to be synchronized with the main coordinate determined based on the GPS signal, and the sub The reference speed, which is the movement distance per pulse, is measured from the speed pulse using the coordinates, and the azimuth correction for correcting the displacement of the electronic compass 65 is periodically performed in the background using the sub-coordinates. . As a result, the subunit 12 can increase the accuracy of the speed data and the azimuth correction data.
Then, coordinate data related to high-precision main coordinates or sub-coordinates, and velocity data and azimuth correction data associated with the coordinate data are recorded in the sub storage medium 42. As a result, even if the vehicle speed signal or the geomagnetic sensor is out of order, it can be restored immediately without being restarted or reset.
On the other hand, in an area where it is difficult or impossible to receive GPS signals from GPS satellites, velocity data and Based on the azimuth correction data, the distance data and the direction data of the updated coordinates with respect to the reference coordinates are determined, and the positions of the sub-coordinates are sequentially specified. Thereby, even if it is a place where a GPS signal is interrupted, the current position can be displayed on the electronic map displayed on the monitor of the main unit.

According to the GPS smart system 10 according to the present embodiment, portable terminal devices that are widely used in the main unit 11 can be used. Thereby, the introduction cost and maintenance management cost of a navigation apparatus can be suppressed significantly.
Further, the main unit 11 and the subunit 12 are connected by the wireless communication line 13. Thereby, it is possible to freely install the mobile terminal device as the main unit 11 without particularly selecting a location. Therefore, it can be arranged directly above the meter panel or on the dashboard with the monitor screen oriented toward the driver, improving usability. And by connecting with the radio | wireless communication line 13, the subunit 12 can be arrange | positioned in an inconspicuous position. As a result, it is possible to prevent the wiring from being exposed in the vehicle and the appearance of the subunit 12 from being exposed and damaging the appearance.

10 ... GPS smart system, 11 ... Main unit, 12 ... Sub unit, 13 ... Wireless communication line,
20 ... main storage medium, 21 ... display unit, 22 ... main control unit, 23 ... main communication unit,
24 ... monitor, 25 ... main control means, 26 ... first positioning means, 27 ... bidirectional communication means on the main unit side, 28 ... main radio section, 29 ... main unit side GPS receiving means, 30 ... main GPS antenna,
40 ... sub communication unit, 41 ... sub control unit, 42 ... sub recording medium, 43 ... power source, 43a ... power input terminal, 43b ... earth terminal,
44 ... Bi-directional communication means on the subunit side, 45 ... Slave radio section, 46 ... GPS receiving means, 47 ... Sub GPS antenna,
48 ... second positioning means, 49 ... sub-coordinate forming means,
55 ... Sub-coordinate arrangement means, 56 ... Sub-coordinate identification means, 57 ... Distance measurement means, 58 ... Direction measurement means,
60 ... speed pulse detecting means, 60a ... vehicle speed signal input terminal, 61 ... reference speed setting means,
65 ... Electronic compass, 66 ... Geomagnetic sensor,
70: Signal input / output unit,
80 ... Audio signal output terminal, 80a ... Speaker, 81 ... Audio signal input terminal, 81a ... Microphone, 82 ... Infrared signal input terminal, 82a ... Infrared light receiving sensor, 82b ... Remote control.

Claims (4)

A main storage medium in which an electronic map based on online map information data provided via the Internet is recorded in a readable manner;
A display unit having a monitor for displaying the electronic map;
A main control unit that controls scrolling and enlargement / reduction display of the electronic map, and controls display of the electronic map so that predetermined coordinates on the electronic map are located at the center of the monitor;
And a main communication unit having a bidirectional communication means having a main wireless unit that communicates with the slave wireless unit bidirectionally via a wireless communication line,
A main unit comprising a smartphone, a mobile phone, a tablet-type terminal device or a similar mobile terminal device, and
A bi-directional communication means having a slave radio section that communicates with the main radio section bidirectionally via the radio communication line; and a sub-communication section having a GPS receiving means having a GPS antenna for receiving a GPS signal;
Positioning means for positioning the main coordinates based on the GPS signal, and sub-coordinate forming means for forming sub-coordinates arranged at substantially the same positions as the positions of the main coordinates that are periodically formed. A sub-control unit that controls to arrange the sub-coordinates at a position synchronized with the main coordinates, with respect to the position of the main coordinates periodically formed based on
And a sub-storage medium for recording the coordinate data relating to the main coordinates and the sub-coordinates in a readable manner,
A subunit having
When the GPS signal can be received,
In the subunit, positioning the main coordinates and forming the sub coordinates arranged in synchronization with the main coordinates,
When the GPS signal is difficult to receive or cannot be received,
In the subunit, the sub-coordinate is formed so as to overlap the coordinate where the main coordinate is to be arranged when a GPS signal can be received,
Coordinate data related to the main coordinate or the sub-coordinate is transmitted from the subunit to the main unit via the wireless communication line,
Regardless of the reception state of the GPS signal, the main unit displays the main coordinate or the sub-coordinate based on the coordinate data superimposed on the corresponding predetermined coordinate on the electronic map. GPS smart unit. The sub-coordinate forming means includes
Sub-coordinate arrangement means for periodically arranging the sub-coordinates at substantially the same position as the main coordinates;
Among the plurality of arranged sub-coordinates, the latest two sub-coordinates are used as the reference coordinates, the subsequent sub-coordinates are used as updated coordinates, and the plurality of arranged sub-coordinates are identified. Sub-coordinate identifying means for assigning a code;
Distance measuring means for measuring a distance between the reference coordinates and the updated coordinates;
Azimuth measuring means for measuring the direction of the updated coordinates viewed from the reference coordinates,
When the sub-coordinate is arranged and adjacent to the sub-coordinate and the other sub-coordinate are the reference coordinate and the update coordinate,
2. The GPS smart system according to claim 1, wherein a position of the updated coordinate is determined based on a relative distance and direction of the updated coordinate with respect to the reference coordinate. In the distance measuring means,
A speed pulse detecting means for detecting a speed pulse periodically emitted from a vehicle, a ship, an aircraft, or a moving body similar to these,
The number of the speed pulses detected by the speed pulse detecting means between one main coordinate and the other main coordinate is counted, and a reference between the reference coordinates and the update coordinates synchronized with both the main coordinates Providing a reference speed setting means for setting the speed,
When the GPS signal is receivable,
Measuring a distance between one main coordinate and another main coordinate based on the GPS signal, and setting a reference distance between the reference coordinate and the update coordinate;
By dividing the reference distance by the number of speed pulses counted by the reference speed setting means, a reference speed consisting of a moving distance per pulse is set,
When the GPS signal is difficult to receive or cannot be received,
The distance between the adjacent sub-coordinates periodically arranged by the sub-coordinate arranging means is
Calculate from the reference speed and the number of speed pulses counted between one sub-coordinate and the other sub-coordinate,
The GPS smart system according to claim 2, wherein a distance between one adjacent sub-coordinate and the other sub-coordinate is measured.   3. The GPS smart system according to claim 2, wherein the direction measuring unit includes a geomagnetic sensor that detects geomagnetism, and is an electronic compass that measures an azimuth based on the geomagnetism detected by the geomagnetic sensor.

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