JP3652775B2 - GPS navigation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a GPS navigation device that receives a signal transmitted from a GPS (GLOBAL POSITIONING SYSTEM) satellite and measures the position and speed of a moving body such as a ship to be mounted.
[0002]
[Prior art]
GPS navigation devices mounted on mobile bodies such as ships are well known, but GPS transmits radio signals from GPS satellites launched in a predetermined number of orbits around the earth and these signals are mounted on ships. The GPS navigation device receives and measures the pseudorange and Doppler frequency with the satellite, and demodulates the transmitted navigation data to obtain the position and velocity of the satellite that transmitted the signal as information, and the pseudorange and Doppler frequency Based on the satellite position and velocity information, a navigation equation is established with the position and velocity of the moving body as unknowns, and by solving this equation, the position and velocity of the moving body (more precisely, the GPS antenna) (hereinafter referred to as this) Is abbreviated as positioning information).
[0003]
[Problems to be solved by the invention]
As described above, in the GPS navigation apparatus, the required positioning information is positioning information based on the position of the GPS antenna, and normally the GPS antenna is attached to a predetermined position of the moving body and moves in parallel with the moving body. Therefore, the error does not become a problem.
However, when the moving body is a ship, for example, rolling, pitching, yawing, etc. occur due to aging, etc., and this causes the antenna to swing greatly apart from the movement of the moving body to measure the wrong position and speed. And recorded.
[0004]
That is, ship positioning information is usually measured and recorded at the center position of the ship, and if a GPS antenna is installed at this center position, no significant error will occur in the positioning information even if the ship is rolling, pitching or yawing. However, the GPS antenna is usually installed at a position that is high (far) away from this center position because of the necessity of receiving radio waves from satellites, etc., so if rolling, pitching, yawing, etc. occur, this movement Is added to the GPS antenna, and the antenna is greatly swung apart from the movement of the moving body, and an incorrect position and velocity are measured and recorded.
And in navigation recording, since positioning information is measured and recorded sequentially based on the previous data, once an erroneous measurement is recorded, the error cannot be easily removed.
This problem is particularly noticeable in DIFFERENTIAL-GPS in which the error of SA (SELECTIVE AVAILABILITY) is removed.
[0005]
The present invention has been made to solve such a problem, and provides a GPS navigation apparatus capable of measuring accurate positioning information even in a situation where a large swing is applied to an antenna due to an unnatural movement of a moving body. The purpose is to do.
[0006]
[Means for Solving the Problems]
The GPS navigation apparatus according to the present invention includes a first GPS antenna and a second GPS antenna that are different in distance from each other on a same straight line in a height direction of the ship from a measurement point determined on the ship as a moving body. The two GPS antennas receive signals from the satellites, calculate positioning information at the respective antenna positions, and are based on known distances from the measurement points to the first and second antennas, respectively. A means for obtaining positioning data of the measurement points by a proportional distribution method is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the GPS navigation apparatus of the present invention, the moving body is, for example, a ship, and even if rolling, pitching, or yawing is performed, a position that is not affected as much as possible is determined as a measurement point. The first GPS antenna and the second GPS antenna that receive the signals from the satellites with the two GPS antennas to calculate the positioning information of the respective GPS antennas. The positioning data of the measurement point is obtained by the proportional distribution method based on the known distance to the second antenna.
[0008]
That is, as shown in FIG. 1, the center 10 of the ship 1 is determined as a measurement point, the first GPS antenna 20 is provided at a distance A on the same straight line from this measurement point, and the distance B { A second GPS antenna 30 is provided at a distance (A + B)} from the measurement point 10.
As shown in FIG. 2, the first GPS antenna 20 and the second GPS antenna 30 are connected to the GPS receivers 21 and 31 and the positioning information calculation units 22 and 32, respectively, and measure the positioning information at the positions of the antennas. It outputs to the positioning information calculation part 100.
[0009]
Here, the position of the measurement point is P ₀ , the speed is V ₀ , the position of the first antenna 20 is P ₁ , the speed is V ₁ , the position of the second antenna 30 is P ₂ , and the speed is V _2. By the proportional distribution method based on the known distances A and B, the relationship between the position and speed at each point is as follows.
(A + B) P ₁ = B × P ₀ + A × P ₂ (1)
(A + B) V ₁ = B × V ₀ + A × V ₂ Formula (2)
These equations (1) and (2) are
P ₀ = {(A + B) P ₁ −A × P ₂ } / B (3)
V ₀ = {(A + B) V ₁ −A × V ₂ } / B...
That is, the position P ₀ and the velocity V ₀ of the measurement point 10 are obtained by using the expressions (3) and (4), respectively, as the position P ₁ and the speed V _{1 of the first} antenna 20 and the position P ₂ and the position P ₂ of the second antenna 30. can be determined by the speed V _2, the measurement point positioning information computation unit 100 performs this operation, and outputs the positioning information at the measurement point 10.
[0010]
Since the measurement point 10 determines a position that is not affected as much as possible even when the ship 1 is rolling, pitching, or yawing as described above, the GPS antenna greatly fluctuates due to the unnatural movement of the moving body. Even if the above is added, it is possible to provide an apparatus that outputs accurate positioning information of the moving body 1 without causing erroneous measurement.
[0011]
In the above-described embodiment, an example of an unnatural movement of a moving body is described by rolling a ship, but this is an example, and the relative position between the moving body and the antenna is temporarily different. It goes without saying that all such unnatural movements of mobile objects are included.
In the description of FIG. 2, the GPS receiver and the positioning information calculation unit are described as two systems. However, if the positioning information of the two antennas can be calculated and processed in parallel, these are one system. It can be set as this structure.
[0012]
【The invention's effect】
As described above, the GPS navigation device of the present invention can measure accurate positioning information even under a situation in which a large fluctuation or the like is applied to the antenna due to an unnatural movement of a moving body, and is highly accurate and highly reliable. There is an effect that positioning information can be obtained.
The effect is particularly high in DIFFERENTIAL-GPS in which the error of SA is eliminated and the error of the rocking motion of the ship becomes remarkable.
[Brief description of the drawings]
FIG. 1 is a layout diagram for explaining a proportional distribution method according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a device configuration example according to an embodiment of the present invention.
[Explanation of symbols]
1 Mobile body (ship)
10 measurement point 20 first GPS antenna 21 GPS receiver 22 positioning information calculation unit 30 second GPS antenna 31 GPS receiver 32 positioning information calculation unit 100 measurement point positioning information calculation unit

Claims (1)

In a GPS navigation apparatus that is provided on a moving body and outputs information on the moving position and speed of the moving body (hereinafter, abbreviated as positioning information) by GPS,
A first GPS antenna and a second GPS antenna having different distances on the same straight line in the height direction of the ship from a measurement point determined on the ship as a moving body , the two GPS antennas And receiving the signals from the satellites, calculating the positioning information at the respective antenna positions, and using the proportional distribution method based on the known distances from the measurement points to the first and second antennas, respectively, Means for obtaining positioning data;
A GPS navigation apparatus comprising:

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