JPH0611560A - GPS positioning device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a GPS positioning device that further narrows the error range with respect to a positioning position caused by an error in the orbit information of GPS satellites and improves positioning accuracy. [Structure] The signal detection unit 10 detects a plurality of signals from five or more satellites, selects a satellite signal to be used for positioning from the received signals of the plurality of satellites, and
Or, the current position obtained by the positioning calculation from the signals of four satellites, the error range obtained from the signals of each satellite, and the direction of the satellite are obtained, and further, three or four satellites of the positioning point A common part of the error region calculation unit 40 that obtains an error region from the error range obtained by the positioning unit, and the error region obtained in the same manner for three or four satellites that include at least one satellite other satellite. And a common error area calculation unit 50 for calculating a plurality of combinations,
By changing the combination of the positioning satellites, several error areas are obtained, and the intersections of the error areas are obtained to further limit the error areas and improve the accuracy.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a global positioning system (G
PS), that is, a GPS positioning device that determines the position where the radio waves are received by receiving the radio waves transmitted from a plurality of satellites.

[0002]

2. Description of the Related Art In recent years, a GPS positioning device is required to have two-dimensional or three-dimensional position information of a moving body such as a vehicle or a ship, and its accuracy and response speed are both highly accurate and high speed. Required.

A conventional GPS positioning device will be described below. The conventional GPS positioning device determines the position of a measuring point by measuring the distance between the satellite and the measuring point with the position of the measuring point as a reference. Four satellites are required to determine the position of the measurement three-dimensionally, for example in latitude and longitude. Positioning is governed by the accuracy of signal measurement of code signals from each satellite, the accuracy of satellite orbit information, and the positional relationship of four satellites in the sky.

Conventionally, the GD is used as a selection criterion for selecting which four satellites should be used for positioning from the satellites seen in the sky.
OP (General Dilution of Pr)
There is a decision: general delusion of precision. The GDOP is determined by the arrangement of four satellites, and a combination of satellites having a small value is used for positioning. GDOP is a four-dimensional coordinate system x, y, z, t
The direction cosine when the i-th satellite is seen from the station at (time)

[0005]

[Equation 1]

Then, the counting matrix H consisting of the direction cosines of four satellites

[0007]

[Equation 2]

Is defined as follows.

[0009]

[Equation 3]

An actual positioning device performs positioning while calculating this GDOP.

[0011]

However, in the above-mentioned conventional method, an error in the positioning point due to a combination of satellites occurs due to an error in the orbit information, and the error reaches several hundred meters.

The present invention solves the above-mentioned problems of the prior art, and when receiving four or more satellites, by changing the combination of satellites and calculating the error range, it is possible to further limit the error range. To aim.

[0013]

In order to achieve this object, the present invention provides a signal detector having a receiving channel for detecting a plurality of signals from five or more satellites, and positioning from the received signals of the plurality of satellites. A satellite selection unit for selecting the satellite signals used for the current position, the current position obtained by positioning calculation from the selected 3 or 4 satellite signals, the error range obtained from the signals of each satellite, and the direction of the satellite; Including a positioning unit that determines the error region, an error region calculation unit that determines the error region from the error range of the positioning unit of three or four satellites for the positioning point, and at least one satellite A common error area calculation unit for calculating a common portion of the three or four satellites with the error area similarly obtained is provided for a plurality of combinations.

[0014]

According to the present invention, by changing the combination of positioning satellites according to the above configuration, some error areas are obtained, and the intersections of the error areas are obtained, whereby the error areas are further limited and the accuracy is improved. Is.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the essential parts of a GPS positioning apparatus according to an embodiment of the present invention. In FIG. 1, 1
0 is a signal detection unit having a plurality of reception channels of 5 or more satellites, 20 is a satellite selection unit that selects a satellite to be used for positioning from the reception satellites, and 30 is a positioning point from GPS satellite signals of 3 or 4 satellites. Positioning unit that determines the error range of each satellite,
Reference numeral 40 is an error area calculation unit for obtaining an error area and direction of each satellite, and an error area for the positioning point, and 50 is an error obtained in the same manner as other satellites with three or four satellites including at least one satellite. It is a common error area calculation unit that takes a common area with a plurality of sets.

In the above configuration, the error area limitation will be described below. First, the satellite signal detected by the signal detection unit 10 is arbitrarily combined with the satellite by the satellite selection unit 10. Next, the positioning unit 30 calculates positioning points in the combination, and further, receiver measurement error,
The sum of the error of each satellite such as orbit information error, ionospheric delay correction error, and troposphere delay correction error is calculated. In addition, when performing three-satellite positioning, generally, altitude information is obtained from the outside to perform positioning, and the error at this time is replaced with the altitude error. Further, the error area calculation unit 40 calculates an error area for the error range of each satellite obtained by the positioning unit 30.

A method for calculating the error area of the satellite in the combination from the error range of each satellite will be described using the error area shown in FIG.

First, the satellites currently receiving are A, B,
It is assumed that there are five satellites C, D, and E, the error range and the direction taken by each satellite are as shown in FIG. 2, and the center point is the position calculated by satellite positioning by four satellites. At this time, consider the case where four arbitrary satellites ABCD are selected. Place satellite A on the center point, and place satellite B at both ends
When the satellite C is translated to each end of the satellite C and the satellite D is translated to each end of the satellite C, the result is as shown in FIG. This is the error area for this satellite combination. In the same way, satellite B,
FIG. 4 shows the error areas obtained for C, D, and E. With respect to the error region obtained as described above, the common error region calculation unit 50 then receives the error region calculation unit 4
A common error area is calculated by superposing each of several error areas obtained at 0 as shown in FIG. 5 and obtaining only the overlapping portion of all error areas.

In order to improve the calculation efficiency, 3,
Alternatively, the shortest and longest line segments connecting the respective vertices in the error region obtained from the GPS satellite signals of four satellites are obtained, and at least one or more other satellites are included 3, or 4
Excludes the calculation of the common area of the error region where the shortest line segment exceeds the shortest longest line segment of other error regions by finding the shortest and longest line segments in the error region obtained in the same way as for each satellite. The common area calculation efficiency improving section may be provided between the error area calculating section 40 and the common error area calculating section 50.

Alternatively, from the GPS satellite signals of all satellites,
Find the error range and direction of each satellite (this is called the error vector), and select the four satellites so that the scalar product of the error unit vectors on the both sides of the four adjacent satellites in the horizontal direction is closest to 1. , And the vector whose scalar product with the sum of the two vectors becomes 0 is selected, and four satellites having four vectors sandwiching the vector are selected, and the common area calculated by these two sets is calculated as the common error area. Calculation unit 5
You may carry out with 0.

[0022]

As described above, according to the present invention, an error area is obtained from some combinations of satellites being received, and the error area is limited from the overlap thereof. The reliability of the positioning result can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a GPS positioning device according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing an error range in the GPS positioning device.

FIG. 3 is a conceptual diagram showing an error range in the GPS positioning device.

FIG. 4 is a conceptual diagram showing an error range in the GPS positioning device.

FIG. 5 is a conceptual diagram showing an error range in the GPS positioning device.

[Explanation of symbols]

 10 signal detection unit 20 satellite selection unit 30 positioning unit 40 error region calculation unit 50 common error region calculation unit

Claims (3)

[Claims] 1. A signal detection unit having a reception channel for detecting a plurality of signals from five or more satellites, and a satellite selection unit for selecting a signal of a satellite used for positioning from the received signals of the plurality of satellites. A positioning unit that obtains the current position obtained by the positioning calculation from the signals of three or four satellites, the error range obtained from the signals of each satellite, and the direction of the satellite, and further 3 for the positioning point, Alternatively, an error region calculation unit that obtains an error region from the error range obtained by the positioning unit of four satellites, and an error similarly obtained by three or four satellites including at least one satellite other satellite A GPS positioning device, comprising: a common error region calculation unit that calculates a common portion with a region for a plurality of combinations. 2. The shortest and longest line segments connecting the vertices in the error region obtained from the GPS satellite signals of three or four satellites are obtained, and at least one or more other satellites are included in the three or four satellites. Calculate the shortest and longest line segments in the same error region of the satellite and find the common region of the error region where the shortest line segment exceeds the shortest longest line segment of other error regions. The GPS positioning device according to claim 1, wherein the common area calculation efficiency improving section to be improved is provided between the error area calculating section and the common error area calculating section. 3. An error unit vector which is located on both outer sides of four adjacent satellites in the horizontal direction, by obtaining the error range and direction of each satellite from GPS satellite signals of all satellites received by the GPS satellite receiver. 4 satellites are selected so that the scalar product of is closest to 1, and the vector whose scalar product with the sum of the two vectors becomes 0 is obtained, and 4 satellites with 4 vectors sandwiching that vector are selected. Selected,
The GPS positioning device according to claim 1, wherein the common error area calculation unit is provided with a common area calculation unit obtained by the two sets.