JPH0868642A - Gps navigation system - Google Patents

Abstract

PURPOSE: To modify setting conditions such as a prediction horizontal position error (FOM value) etc., and to obtain a GPS navigation system for checking whether the position-measurement data with a required accuracy are obtained or not by providing a display for showing the judgment result of the accuracy of position measurement data and a means for switching a display means. CONSTITUTION: A GPS signal from a GPS satellite is received by the signal reception antenna of a GPS sensor 1 and is subjected to signal processing. At this time, FOM value indicating the signal reception state is calculated from the detected position measurement data. The FOM value is compared with the display conditions of a preset display 2, an LED is lit when the FOM value is included in the display conditions, and then it is reported to a user that the position measurement data are calculated within a required accuracy. If a position is different from an actual position even if the LED lights up, a PC(Personal Computer) 5 is connected to a GPS sensor 1 and the display conditions of the display 2 are switched with a high accuracy. If the LED does not light up, the installation location of the GPS sensor 1 is modified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to GP from GPS satellites.
The present invention relates to a GPS navigation system that calculates the position of a moving body by receiving an S signal.

[0002]

2. Description of the Related Art Conventionally, a global positioning system (GPS) which receives a GPS signal from a GPS satellite and generally detects the current position or moving speed of a moving body such as a person, a ship, an aircraft, or an automobile is known. GP used
S navigation systems are known.

The above GPS navigation system normally receives GPS signals from a plurality of GPS satellites, selects 3 to 4 GPS satellites having a good reception state, and determines the current position of the mobile body such as latitude, longitude, altitude, etc. Calculate positioning data,
The present position of the moving body is calculated.

The position accuracy of the positioning data depends on the reception state of the GPS signal, and the reception state depends on the GPS.
Figure of merit (hereinafter, FOM value) that quantified the expected horizontal position error, which is a measure of the convergence of the data in
Or a value (hereinafter, DOP value) indicating how the geometric position of the satellite influences the direction of the position estimation value,
For example, the FOM value is represented by a value of 1 to 9, where the expected horizontal position error is less than 7 meters is 1, 7.5 to 12.5 meters is 2, 12.6 to 25 meters is 3, 26 to 50.
Meters are 4, 51-250 meters are 5, 251-
It is indicated as 6 when 500 meters, 7 when 501 meters or more, and 9 when the data does not converge.

Further, this value is inversely proportional to the positioning rate, which is represented by the number of times the GPS signal is received and the positioning data is calculated in one minute. If this value is small, the number of calculations per minute increases. If this value becomes large, the number of calculations per minute will decrease.

Therefore, when such an FOM value becomes large, the positioning rate decreases and the measurement error becomes large, and the positioning data deviated from the actual position is calculated.
The data exceeding the M value was not treated as positioning data.

For example, in a car navigation system mounted on an automobile, the vehicle travels on a road in an urban area where there are many obstacles such as buildings and steel towers, and on a highway or a suburban road with few obstacles. Since the reception state of the GPS signal greatly changes depending on the case, the position accuracy of the positioning data also largely changes.

Further, the required accuracy of the positioning data to be used varies greatly depending on the road on which the vehicle travels. For example, when driving on urban roads, the roads are dense,
Highly accurate positioning data with FOM values of 1-2 are required,
Further, when traveling on a highway or a road in the suburbs, because the road is straight and the density of the road is low, the FOM value of 1 to 4 does not require very high accuracy.

Generally, the accuracy of such positioning data is
The position of the GPS antenna largely depends on the position of the GPS antenna. For example, when the GPS antenna is mounted inside a vehicle, the accuracy of the positioning data changes at the center or edge of the front dashboard.

However, the accuracy of this positioning data is GP
In an arithmetic device connected to the S sensor, for example, in a car navigation system, the map and the speed are displayed on the arithmetic device. Therefore, the accuracy of the positioning data actually required depends on the position of the GPS antenna. It was difficult to confirm easily whether it was obtained.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is an F which indicates the accuracy of positioning data.
An object of the present invention is to provide a GPS navigation system that can easily confirm whether or not the accuracy of positioning data according to the required accuracy can be obtained by changing the setting conditions such as the OM value.

[0012]

A GPS navigation system according to the present invention has a function of receiving GPS signals from GPS satellites to calculate positioning data of a mobile unit and determining the accuracy of the positioning data. A sensor 1 and a display device 2 for displaying the determination result of the accuracy of the positioning data are provided, and the display condition of the display device 2 can be switched.

[0013]

According to the GPS navigation system of the present invention, a GPS sensor 1 having a function of receiving GPS signals from GPS satellites, calculating positioning data which is the current position of a moving body, and judging the accuracy of the positioning data 1 And the display device 2 for displaying the determination result of the accuracy of the positioning data, and the display condition of the display device 2 can be switched, so that the display condition can be switched according to the accuracy of the required positioning data. Therefore, it is possible to confirm whether or not the GPS sensor 1 is performing positioning as required.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[0015]

1 is a block diagram of a GPS navigation system according to the present invention.

The GPS navigation system according to the present invention, as shown in FIG. 1, has a GPS sensor 1 and a display device 2.
And a setting device 3.

The above GPS navigation system has a G
A plurality of Gs equipped with the PS sensor 1 and received by the receiving antenna
GPS signals sent from PS satellites are processed to calculate positioning data such as longitude, latitude, and altitude of the receiving position, and the moving speed and moving distance of the moving body are calculated by an internal arithmetic device. . At this time, the reception state of the GPS signal of the receiving antenna is calculated from the positioning data.

The display device 2 includes the GPS sensor 1
It displays the reception status of the GPS signal obtained in
EDs, lamps, and panel display boards are used.

The display conditions of the display device 2 are set by the setting device 3
Can be set by means of a setting switch attached to the GPS sensor 1 or a personal computer having a communication cable connected to the GPS sensor 1.

The operation of the GPS navigation system having the above structure will be described.

FIG. 2 is a block diagram of a GPS navigation system according to an embodiment of the present invention.

First, the GPS signals sent from the four GPS satellites are received by the receiving antenna of the GPS sensor 1,
This GPS signal is processed. Positioning data such as the longitude, latitude, and altitude of the reception position are calculated by signal processing, and the moving speed and moving distance of the moving body are calculated by an internal arithmetic device. At this time, the GPS is determined by the above positioning data.
The FOM value indicating the reception state of the reception antenna that receives the GPS signal from the satellite is calculated.

This FOM value is compared with the preset display condition of the display device 2, and if included in the display condition, the LED 4 which is the display device 2 is turned on and the positioning data is calculated within the required accuracy. If the display condition is not included, the LED 4 is not turned on.

For example, here, the LED 4 is turned on,
Although it was confirmed that the positioning data was calculated within the required accuracy, the position was confirmed by checking it against the map, but it is assumed that the position is different from the actual position.

Therefore, RS-232C is added to the GPS sensor 1.
Was connected to the personal computer 5. Then, with this personal computer 5, the display condition of the LED 4 of the display device 2 was changed with high accuracy.

However, in the place where the GPS sensor 1 is currently installed, it cannot be confirmed that the LED 4 is lit, and if it is confirmed that the positioning state is insufficient, the installation position of the GPS sensor 1 is set to the position where the LED 4 is lit. It is possible to change and obtain an appropriate positioning state.

[0027]

By using the GPS navigation system of the present invention, it is possible to change the setting condition for displaying the accuracy of the positioning data, and whether the accuracy of the positioning data according to the required accuracy can be easily obtained. You can check. Further, by checking the display device, it is possible to know the mounting position of the GPS antenna that can obtain the positioning data with required accuracy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a GPS sensor (1) according to the present invention.

FIG. 2 is a configuration diagram of a GPS sensor (1) which is an embodiment of the present invention.

[Explanation of symbols]

 1 GPS sensor 2 display device 3 setting device 4 LED 5 personal computer

Front page continuation (72) Inventor Koji Maeda 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor, Michinobu Usagawa, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Co., Ltd.

Claims (1)

[Claims] 1. A GPS sensor (1) having a function of receiving a GPS signal from a GPS satellite to calculate positioning data of a moving body and judging the accuracy of this positioning data, and a judgment of the accuracy of this positioning data. A GPS navigation system, comprising: a display device (2) for displaying a result, wherein display conditions of the display device (2) can be switched.