JP2000205871A - Method for deciding own vehicle road position of multi- tiered road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate between an upper road and a lower road of a multi-tiered road without adding new unit and component to a navigation apparatus, by discriminating them as the upper road when a right or left side of a satellite is observed toward an advancing direction or as the lower road when it is not observed. SOLUTION: In the case of traveling an own vehicle on a multi-tiered road, an upper road and a lower road are discriminated as the upper road when a right or left side of a satellite is observed toward an advancing direction or as the lower road when the right or left side of the satellite is not observed. For example, at a vehicle A traveling on a road of the upper road, a reception from a GPS satellite existing in the sky is not shielded except by a part of a first building. At a vehicle B, there is nothing to shield it in the sky ahead thereof, but the sky cannot be observed by shielding by the building and an elevated facility in the right and left sky. At a vehicle C, the sky cannot be observed except a part ahead thereof. Whether a range of a GPS satellite to be observed is wide or narrow is quantitatively handled and defined as a position measuring ratio (%)=(distance effectively run by a GPS position measurement)×100/(run distance).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the position of an own vehicle road on a multi-layered road, and more particularly, to a method for determining the position of an own vehicle on a multi-layered road without adding a new device or part to a navigation device. Is determined.

[0002]

2. Description of the Related Art Conventionally, a navigation system is generally known as a tool for knowing the position of a vehicle. FIG. 6 shows an outline of a conventionally known navigation system. As shown in FIG. 6, the navigation system includes a GPS satellite 28 and a GPS satellite.
Vehicle position calculating means 20 for calculating the position of the vehicle based on data from 28, information searching means 23 for searching for a facility or the like to be used, and route searching means for searching for a route to the facility 21; guidance means 22 for guiding the vehicle along the searched route; display control means 25 for displaying on a display 26 such as a liquid crystal display or a CRT display;
Map data 27 stored in a storage medium such as a CD-ROM
It is composed of

Here, the outline of the measurement of the position of the vehicle based on GPS satellites will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 shows an example in which three GPS satellites in the sky can be seen from the own vehicle. If this is shown in the sky map of FIG. 8, GPS satellites can be seen in three different directions with respect to the traveling direction of the own vehicle, so that correct positioning is possible in such a case.
In other words, the correct road is obtained using map matching using the own vehicle direction and the road direction.If the GPS satellites are in such a state, the position of the own vehicle and the road on which the own vehicle is running are correctly determined. it can.

However, when the vehicle travels on a multi-layered road consisting of parallel roads, it is difficult for the conventional navigation system to determine the position of the road.

[0005] In other words, since a parallel road is divided into a multi-layered road, that is, an upper layer and a lower layer, and the position on the horizontal plane is the same, it is difficult to correctly determine which position is located. Become. As a result, when using a highway map (map for Tokyo Metropolitan Expressway), voice guidance, and an emergency call system, there is a problem that its reliability is not sufficiently guaranteed.

[0006]

In order to solve this problem, conventionally, a gyro for detecting the pitching of the vehicle is newly provided, and the vehicle is climbed up a slope for entering a road laid on an elevated road. Alternatively, it is detected whether the vehicle has traveled from there, and it is determined whether the vehicle is traveling on an elevated road (upper layer) or a planar road under the elevated road (lower layer). However, in order to realize this concept, it is necessary to install a new gyro,
There is a problem that the cost of the navigation device increases.

The present invention has been made in order to solve the above problems.
It is an object of the present invention to provide a method for determining the position of a vehicle road on a multi-layer road capable of discriminating an upper layer and a lower layer of a multi-layer road without adding a new device or component to the navigation device.

[0008]

According to the present invention, a method for determining the position of a vehicle on a multilayered road according to the present invention determines the upper layer if the left and right satellites are visible in the traveling direction, and if the vehicle is not visible, the lower layer. It is characterized by doing.

Thus, it is possible to determine the upper layer and the lower layer of a multi-layer road without adding a new device / part to the navigation device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that, when the vehicle is running on a multi-layered road, if the left and right satellites are visible in the traveling direction, the upper layer is determined and if not, the lower layer is determined. It is a method for determining the position of the own vehicle road on a multi-layer road, and without adding new devices and parts to the navigation device, the upper layer of the multi-layer road,
It has the effect that the lower layer can be determined.

[0011] The invention described in claim 2 of the present invention provides:
A self-vehicle road position determination method for a multi-layered road, characterized in that if the upper right satellite in the traveling direction is visible in the traveling direction of the vehicle, the vehicle is determined to be the upper layer, and if not, the lower layer is determined. It is possible to determine the upper layer and the lower layer of a multi-layer road without adding new devices and parts to the road.

Further, the invention according to claim 3 of the present invention provides:
3. The method according to claim 2, wherein when one of the reception levels from the upper right satellite is lower than the other, it is determined that the vehicle is on the upper layer in an apparent manner. Only the upper layer can be discarded.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a method of determining the position of the own vehicle road on a multilayer road according to the embodiment of the present invention. In FIG. 1, a vehicle A is shown as a vehicle traveling on a road laid on an overpass, and a vehicle B and a vehicle C are shown as vehicles traveling on a road under the overpass. It is also assumed that a first building and a second building that are higher than the elevated road are constructed on both sides of the road. Assuming that each vehicle is equipped with a navigation device capable of calculating its position information using a GPS satellite, the vehicle A traveling on an upper layer road has a GPS satellite existing in the sky. Nothing is found to block reception except for a part of the first building. However,
In the vehicle B, there is no obstruction in the sky in front, but the sky on the left and right cannot be seen by the first building or the elevated facility. Except for, the left and right cannot see the sky.

When this state is shown in the sky map of FIG. 2, it is assumed that the own vehicle position is set at the center of the sky map and the course direction is taken from the bottom of the figure to the top. Then, the vehicle A is slightly obstructed by the first building as shown in FIG.

In the vehicle B, as shown in FIG. 2 (b), nothing obstructs the sky in the traveling direction.
In the left-right direction, you cannot see the sky because of the first building and elevated legs.

In the vehicle C, the sky can be seen in a part of the traveling direction as shown in FIG.
In the left-right direction, you cannot see the sky because of the first building and elevated legs.

As can be seen from FIGS. 2A, 2B and 2C, the shaded area indicating the range where the satellite can be seen is seen in the order of vehicle A → vehicle B → vehicle C. You can see that the range has been reduced.

As the vehicle C advances, FIG.
As shown in (2), when the vehicle enters a place where the left-right direction is opened, for example, an intersection, the sky can be partially viewed in the left-right direction.

As is apparent from the above description, in order to determine the road position on which the vehicle is traveling on a multi-layer road,
A certain degree of prediction can be made depending on whether the visible range of the GPS satellites in the sky is wide or narrow, but in order to treat it quantitatively, the positioning rate is defined as follows. That is, positioning rate (%) = (distance traveled with GPS positioning enabled) x 100 /
(Driving distance) This makes it possible to determine the road position of the own vehicle. This means that, for example, if the total of the sections in which GPS positioning was possible during traveling 1000 m was 800 m, the positioning rate would be 80%, and the positioning rate exceeded the upper-level determination threshold. If it does not exceed the upper and lower discrimination thresholds, it can be said that it is a lower layer.

Here, "GPS positioning is possible" means G
In order to determine the position of the vehicle using PS satellites, it is usually necessary to see at least three satellites. This is based on the same principle as triangulation and the like. If data from more than this number of GPS satellites cannot be obtained, processing is performed as "GPS positioning is impossible".

Therefore, the present invention provides an upper layer when the ratio of the distance of a section where GPS positioning is possible is equal to or higher than a certain upper layer discrimination threshold value, and is performed when the ratio is equal to or less than a certain lower layer discrimination threshold value. The self-vehicle road position on the multi-layer road is determined in such a manner as to be determined as the lower layer. In this case, the lower layer exceptionally has a better positioning rate near the intersection, but the upper layer can determine the position of the own vehicle road on the multi-layer road even if the positioning rate is uniformly high. Note that the discrimination threshold can be determined as appropriate, and is not an absolute value.

Here, the operation of the present invention will be described with reference to the operation flow of FIG. 3 and FIG. FIG. 3 shows a first example of the present invention based on the positioning rate.
St. In step 31, it is determined whether or not the road is a multilayer road section. If no, the process ends without performing the determination. If yes, the process proceeds to step 32, and the positioning rate is calculated. After that, in step 33, upper and lower layer discrimination thresholds corresponding to the traveling distance are retrieved from the table.

In step 34, it is determined whether the positioning rate exceeds the upper threshold. If yes, it is determined that it is the upper layer. If it is no, the process proceeds to step 35, where it is determined whether the positioning rate is smaller than the lower threshold. If yes, it can be determined that it is a lower layer,
If no, it is determined that the upper and lower layers cannot be determined.

FIG. 4 shows a second example of the present invention based on the positioning rate. First, in step (abbreviated as St. in the drawing) 41, it is determined whether or not the road is a multilayer road section. I do. If no, the process ends without performing the determination. If yes, the process proceeds to step 42, and the positioning rate in each 100 m section is calculated every 100 m. Then, in step 43, it is determined whether or not 800 m has elapsed. Where 100m
And 800 m are not absolute values, but should be understood to be appropriate road sections determined by road conditions. Steps
If the condition of 43 is not satisfied, that is, if the determination is no, the process ends without performing the determination. Next, at step 45, it is determined whether or not the difference exceeds a threshold value. If no, it can be determined as an upper layer, and if yes, it can be determined as a lower layer.

As described above, according to the present invention, as shown in FIGS. 2A to 2C, the range in which the GPS satellite radio wave can be received on the lower road is narrower on the sky map.
It may be convinced that the number of GPS satellites that can be received is reduced on average, and the probability that positioning cannot be performed increases.

Also, without depending on the positioning rate, FIG.
According to the sky map shown in (b), it is possible to determine the upper layer if the left and right satellites are visible in the traveling direction, and to the lower layer if the left and right satellites are visible in the traveling direction on the multilayer road.

Furthermore, without depending on the positioning rate, FIG.
From the sky maps of (a), (b) and (c), when the vehicle is traveling on a multi-layered road, it can be determined that the upper layer is seen if the upper right satellite is seen in the traveling direction, and that if it is not seen, the satellite is the lower layer. .

Further, as shown in FIG. 5, a condition for apparently seeing three GPSs by reflection of a building or the like is set. To explain this further, the satellite X and the satellite Y are directly visible, so there is no problem in positioning, but the signal of the satellite Z is reflected by the building, and the conditions for apparently seeing three GPSs are established. However, such a situation is easily identifiable since the signal of satellite Z reflected by the building is weaker than the other satellites X, Y.

Accordingly, from FIGS. 2 (a), 2 (b) and 2 (c), in the case where the vehicle is traveling on a multi-layered road, if the upper right satellite in the traveling direction is visible, the upper layer is determined, and if not, the lower layer is determined. However, if one of the reception levels from the upper right satellite is smaller than the other, it is determined to be an apparent upper layer, and the upper layer is not distinguished only by the reflection of a building or the like.

[0030]

As described above, according to the method for determining the position of a vehicle on a multilayer road according to the present invention, it is possible to determine the upper layer and the lower layer of a multilayer road without adding a new device or component to the navigation device. It has the effect of being able to.

That is, the information necessary for calculating the position of the vehicle using GPS satellites is positioning information, which is used by most navigation devices as information on whether positioning is valid or invalid. Since the method of the present invention uses the method, most of the navigation devices have an effect that they can be used without adding new devices and parts.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method of determining the position of a vehicle on a multilayer road according to an embodiment of the present invention;

FIG. 2 shows a GPS by a vehicle on a multilayer road according to the present invention;
A diagram showing a sky view that the visible range of the satellite is different,

FIG. 3 is a flowchart for explaining a first operation example of the present invention based on a positioning rate;

FIG. 4 is a flowchart for explaining a second operation example of the present invention based on the positioning rate,

FIG. 5 is a diagram showing a situation in which apparent GPS positioning conditions are established by reflection from a building for vehicles on a multi-layered road according to the present invention;

FIG. 6 is a block diagram illustrating a configuration of a conventional navigation system;

FIG. 7 is a diagram showing an example of a case where general GPS positioning is possible;

FIG. 8 is a diagram showing an example in which general GPS positioning is possible on a sky map.

[Explanation of symbols]

 20 Vehicle position calculation means 21 Route search means 22 Guidance means 23 Information search means 24 Memory 25 Display control means 26 Display means 27 Map data 28 GPS satellite

Claims (3)

[Claims] 1. A method for determining the position of a vehicle on a multilayer road, wherein the vehicle travels on a multilayer road when the left and right satellites are visible in the traveling direction, the upper layer is determined. 2. A self-vehicle road position discrimination method for a multi-layered road, characterized in that, when the vehicle travels on a multi-layered road, the upper right satellite in the traveling direction is determined to be the upper layer, and if not, the lower right layer is determined. 3. The method according to claim 2, wherein when one of the reception levels from the upper right satellite is lower than the other, the vehicle is determined to be an apparent upper layer.