JP3042652B2 - Mobile navigation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile navigation system using GPS.

[0002]

2. Description of the Related Art FIG. 6 is a system configuration diagram showing a configuration of a conventional mobile navigation system. In the figure,
1 is a GPS (Glob) mounted on a vehicle 8 via an antenna 2
al Positioning System) A GPS receiver for receiving signals from the satellites 3a to 3f, 4 is a geomagnetic sensor which is a direction sensor for detecting the traveling direction of the vehicle 8, 5 is a vehicle speed sensor acting as a distance sensor, and 6 is a vehicle speed sensor. A controller 7 for determining the current position is a display for displaying the current position of the vehicle 8 and the like.

Next, the operation will be described. The GPS receiver 1 receives three or more transmission signals among the transmission signals of the GPS satellites 3a to 3f via the antenna 2, and determines the position of the satellite and the vehicle 8-satellite from information contained in the signals. Calculate the distance of Then, based on the calculation results, the current position of the vehicle is calculated by GPS navigation, and the calculated position is transmitted to the controller 6.

On the other hand, the controller 6 inputs information on the traveling direction of the vehicle 8 from the geomagnetic sensor 4 and inputs information on the traveling distance from the vehicle speed sensor 5. Then, the current position of the vehicle 8 by the self-contained navigation is calculated from the initial position of the vehicle 8 and the information thereof. Controller 6 is a GP
When the current position by the S navigation is obtained, it is determined as the final current position of the vehicle 8, and when the current position by the GPS navigation is not obtained, the current position by the self-contained navigation is determined as the final current position. I do. The final current position is displayed on the display 7.

[0005]

The conventional mobile navigation system is constructed as described above.
The S receiver 1 selects the satellite to be used for the current position calculation by the position accuracy priority selection based on the geometrical arrangement of the satellite irrespective of whether or not a signal from the satellite can be received. Therefore, when the antenna 2 is attached to a place where radio waves from a certain direction are shielded by the vehicle body, such as a lid of a trunk of the vehicle 8, there is a problem that GPS navigation may be disabled. . That is, if the radio waves from the GPS satellites 3a and 3b are shielded by the vehicle body in a state where the four GPS satellites 3a to 3d are selected by the position accuracy priority selection, two satellites capable of receiving the radio waves from there are two.
In spite of the fact that there are actually other GPS satellites 3e and 3f that can receive radio waves from there,
Positioning becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mobile navigation system capable of reducing the chance of being unable to perform positioning and improving the frequency of positioning by GPS navigation. Aim.

[0007]

Means for Solving the Problems A mobile navigation system according to the first aspect of the present invention, progressive lateral position of the moving body by GPS navigation radio waves from GPS satellites has performed regions and prior to being shielded is stored Radio wave shielding area
Storage unit and GPS stored in radio wave shielding area storage unit
Areas where radio waves from satellites are shielded and GPs previously executed
It is obtained by S navigation and stored in the radio wave shielding area storage unit.
Reads the heading of the previous moving object, signals from GPS satellite stored in the electric wave shielding region storage portion of the shield that
Area and the heading of the previous moving object
The radio wave shielding range where radio waves from GPS satellites are more shielded
Identify this radio wave shielding area and compare the position of each GPS satellite.
GPS satellites outside the shielding area used for calculating the current position
It provided a satellite selection unit that selects a star is also of a.

[0008]

[Action] satellite selecting unit of the first aspect of the present invention, more than
Since the heading from the previous GPS navigation is used,
Satellite selection even when applied to non-functional vehicles
Can be executed.

[0009]

[Embodiment 1] FIG. 1 is a system configuration diagram showing a configuration of a mobile navigation system according to a first embodiment of the present invention. In the figure, reference numeral 1a denotes a GPS reception processing unit for receiving radio waves from the GPS satellites 3a to 3f, 1b denotes a satellite selection unit for selecting a satellite used for positioning, and 1c denotes a memory for storing a radio wave shielding area (a radio wave shielding area storage). And 6 is a controller for determining the current position of the vehicle 8. In addition, the geomagnetic sensor 4, the vehicle speed sensor 5, and the controller 6 implement a traveling direction calculation unit (traveling direction input unit). Incidentally, the conventional view the same or corresponding parts and its description is omitted the same reference numerals.

FIG. 2 is an explanatory view for explaining a radio wave shielding area. FIG. 2A shows an azimuth shielding area.
(B) shows the elevation angle shielding area.

Next, the operation will be described with reference to the flowchart of FIG. The controller 6 inputs information on the traveling direction of the vehicle 8 from the geomagnetic sensor 4 and inputs information on the traveling distance from the vehicle speed sensor 5. Then, the current position of the vehicle 8 by the self-contained navigation is calculated from the initial position of the vehicle 8 and the information thereof. Then, the satellite selector 1b first reads out information on the radio wave shielding area from the memory 1c (step ST1). In the memory 1c, an azimuth shielding area ± α and an elevation shielding area β corresponding to the antenna mounting position are set when the antenna 2 is mounted (see FIG. 2).

Next, the satellite selection section 1b includes a controller 6
Receives the vehicle traveling direction θ by the self-contained navigation (step ST2), and specifies an area where radio waves from the satellite are shielded (step ST3). That is, the azimuth angle range θ ± α and the elevation angle range ≦ β are specified. Further, the satellite selection unit 1b receives information from any satellite via the antenna 2 and the GPS reception processing unit 1a. Since information from each satellite includes general orbit information of all satellites, the satellite selection processing unit 1b
Can recognize the positions of all satellites.

Then, the satellite selecting section 1b compares the specified radio wave shielding area with the position of each satellite and selects a satellite outside the shielding area as one whose positioning can be used (step ST).
4). In FIG. 1, assuming that the GPS satellites 3a, 3b are within the shielding range, the GPS satellites 3c, 3d, 3e, 3f
Is selected.

After that, the satellite selecting section 1b transmits the GPS satellites 3c and 3c via the antenna 2 and the GPS reception processing section 1a.
The satellite position and the distance to the satellite are calculated using the navigation messages received from d, 3e, and 3f, and the current position of the vehicle 8 is calculated from the result (step ST5). Then, the current position by the GPS navigation is transmitted to the controller 6 (step ST6). Step ST2 above
The satellite selection process and the positioning calculation process in ST6 are sequentially repeated.

When the current position by the GPS navigation from the satellite selection section 1b is obtained, the controller 6 sets the final position as the final position. Otherwise, the controller 6 sets the current position by the self-contained navigation as the final position on the display 7 as the final position. indicate.

In the above embodiment, the geomagnetic sensor 4 and the vehicle speed sensor 5 are used as the traveling direction input unit. However, a direction obtained from road-to-vehicle information such as a sign post and a beacon may be used.

Embodiment 2 FIG. FIG. 4 is a system configuration diagram showing a configuration of a mobile navigation system according to a second embodiment of the present invention. In this case, the satellite selection unit 1d performs a satellite selection process based on the current position of the vehicle 8 obtained by the GPS navigation. Therefore, a geomagnetic sensor and a vehicle speed sensor are unnecessary. The same or corresponding parts as those in the conventional drawings are denoted by the same reference numerals, and description thereof will be omitted.

Next, the operation will be described with reference to the flowchart of FIG. First, the satellite selection unit 1d
The information about the radio wave shielding area is read from c (step ST11). Next, the vehicle traveling direction θ obtained by the previous GPS navigation is received (step ST12). The direction is stored in the memory 1c, for example. Then, an area where the radio wave from the satellite is shielded is specified (step ST).
13). That is, the azimuth angle range θ ± α and the elevation angle range ≦ β are specified. In addition, the satellite selection unit 1d includes the antenna 2 and the G
Information from an arbitrary satellite is received via the PS reception processing unit 1a, and the position of each satellite is recognized.

The satellite selecting section 1d compares the specified radio wave shielding area with the position of each satellite, and selects the GPS satellites 3c, 3d, 3e, 3f outside the shielding area as those whose positioning can be used (step ST14). ).

After that, the satellite selecting unit 1d transmits the GPS satellites 3c and 3c via the antenna 2 and the GPS reception processing unit 1a.
The satellite position and the distance to the satellite are calculated using the navigation messages received from d, 3e, and 3f, and the current position of the vehicle 8 is calculated from the result (step ST15). Then, the current position by the GPS navigation is transmitted to the controller 6 (step ST16). Step ST2 above
The satellite selection process and the positioning calculation process of ST6 are repeated. The controller 6 displays the current position by the GPS navigation from the satellite selection unit 1d on the display 7 as a final position.

[0021]

As described above, according to the first aspect of the present invention, the mobile navigation system is executed before.
The current position by GPS navigation is used to select the current position for satellite selection.
There is no self-contained navigation function
Even when applied to moving objects, GPS navigation
There is an effect that a system with high positioning frequency can be constructed.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a configuration of a mobile navigation system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a radio wave shielding area according to an antenna attachment position.

FIG. 3 is a flowchart illustrating an operation of a satellite selection process in the first embodiment.

FIG. 4 is a system configuration diagram showing a configuration of a mobile navigation system according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of a satellite selection process in the second embodiment.

FIG. 6 is a system configuration diagram showing a configuration of a conventional mobile navigation system.

[Explanation of symbols]

1b, 1d Satellite selection unit 1c Memory (radio wave shielding area storage unit) 3a-3f GPS satellite

Claims (1)

(57) [Claims] 1. A mobile navigation system that calculates a current position from radio waves received from a plurality of GPS satellites and performs navigation using the current position. progress How to position the memory of the mobile by GPS navigation
Is a conductive wave shielding region storage unit is, GPS navigation radio waves from G PS satellite stored in the radio wave shield region storage unit is executed before the area to be shielded
And stored in the radio wave shielding area storage unit.
Reads the heading of the previous moving body, before Symbol wave shielding territory
Radio waves from the GPS satellites stored in the area storage unit
The area to be occluded and the stored advance of the moving object
Identify the radio wave shielding range radio waves are shielded from the previous SL GPS satellites by the whereabouts position, wherein this wave shielding range each GP
A mobile navigation system comprising: a satellite selection unit that compares the position of the S satellite with the GPS satellite outside the radio wave shielding range used for calculating the current position.