JPH0646438B2 - Vehicle route guidance device - Google Patents

Description

The present invention relates to a vehicle route guidance device.

[Prior Art] As a conventional route guidance device for a vehicle, for example, Japanese Patent Laid-Open No.
The one described in JP-A-223017 is known.

This is a GPS (Global Positio) as a position measuring means.
ning system) position measuring device is provided, and a predetermined route guidance is performed while displaying the traveling locus using the current position measured by GPS.

However, such a conventional vehicle route guidance device has a configuration in which the position measured by GPS is displayed as it is, or the current position is displayed while the integrated position is corrected at the position measured by GPS. Therefore, there is a problem that the positioning error of GPS is directly displayed on the displayed map.

When the positioning error of GPS is displayed on the display map as it is, the vehicle position often flies around the route on the map, and the display becomes unnatural.

[Object of the Invention] An object of the present invention is to provide a vehicle route guidance device that solves the above-mentioned problems and that can accurately perform position measurement and provide a natural display.

[Summary of the Invention] In order to achieve the above object, according to the present invention, a vehicle route guidance device is provided with an azimuth detecting means 1 for detecting a traveling azimuth of a vehicle as shown in FIG. A distance detecting means 3 for detecting a current position, a first current position calculating means 5 for calculating a current position from the traveling direction and the traveling distance, and the first current position calculating means 5.
Display means 7 for displaying the current position calculated by the current position calculating means 5, receiving means 9 for receiving radio waves from GPS satellites, and calculating the current position of the vehicle from the radio waves received by the receiving means 9. Second current position calculation means 11 for
The current position storage unit 13 that stores the plurality of current positions calculated by the second current position calculation unit 11, and the traveling direction of the vehicle from the plurality of current positions stored in the current position storage unit 13 A traveling direction calculation unit 15, a road data storage unit 17 that stores the end point coordinates of each road line segment, the distance between each road line segment, and the direction of each road line segment, and the travel distance detected by the distance detection unit 3. According to the traveling direction calculated by the traveling direction calculation means 15, the road data storage means 1
Selection means 1 for selecting a traveling road line segment from 7
9 and the distance of the road line segment selected by the selecting means 19 and the traveling distance detected by the distance detecting means 3 are compared, and when the end point of the road line segment is reached, the first current position calculation is performed. Compensating means 21 for compensating the current position calculated by means 5 to the end point coordinates of the road line segment selected by the selecting means 19 is constituted, and the integral position is calculated at the end position of the straight line-approximated road line segment. As a correction, only the integral position is displayed on the road defined by each line segment.

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

First, briefly explaining the drawings, FIGS. 2 to 9 show an embodiment of the present invention, FIG. 2 is a block diagram of vehicle route guidance equipment, and FIG. 3 is a block map. An explanatory diagram, FIG. 4 is a memory map of an external memory, FIG. 5 is a memory map of road data, and FIG. 6 is a data format of road data. Further, FIGS. 7 (a), (b), and (c) are explanatory views showing an example of use of road data, FIG. 8 is a flowchart of current position calculation processing by GPS, and FIG. 9 is calculation / correction processing of integrated position. It is a flowchart of.

As shown in FIG. 2, the vehicle route guidance device includes a system bus 7, a GPS receiver 8, a CPU 9, and a system R.
OM10, RAM11, sensor interface 1
2, the video RAM 13, the operation panel interface 14, the input operation unit 15, and the external memory 16 are connected to each other.

The sensor interface 12 is connected to a distance sensor 17 that outputs one pulse signal every time the vehicle travels a certain distance, and a direction sensor 18 that detects the traveling direction of the vehicle. A CRT 19 is connected to the video RAM 13. The operation panel interface 14 has a CRT 1
A transparent operation panel (touch panel) 20 provided on the front surface of 9 is connected.

The GPS receiver 8 includes an antenna 8A, receives satellite radio waves from a combination satellite having a good DOP value, measures the vehicle position every predetermined time (for example, 5 seconds), and provides the measured position to the CPU 9. .

Based on the program stored in the system ROM 10, the CPU 9 performs integration (estimation) position and calculation, correction of the integration position, display control of the current position, and various other route guidance processes.

Here, the integrated position is calculated by inputting the output signals (vehicle speed signal and signal direction signal) from the distance sensor 17 and the direction sensor 18 through the sensor interface 12, and integrating the running vector at the current position (reference position). Then, the new current position (estimated position) is obtained.

Further, the correction of the integration position is performed at a predetermined position (road segment end position), as described in detail in FIG.

The CRT 19 is for displaying the current position, displaying the traveling locus, and the like. The operation panel 20 is for inputting a departure place and a destination. The input operation unit 15 is
It is formed by a so-called keyboard, where
It is possible to set various numerical values.

As shown in FIG. 3, the map 21 represented by XY coordinates is displayed.
Are blocks (1-1) and (1-
2) ... (3-3), and the external memory 161 is configured to store various map information for each block.

As shown in FIG. 4, the external memory 16 has various storage areas.

The area start address storage area M1 is an area for storing start addresses of areas M2, M3, ...

The road data storage area M2 includes the start point and end point coordinates of the directly approximated road line segment li shown in FIG. 3, and the line segment l.
This area stores information necessary for route guidance related to i.

As shown in FIG. 5, the road data storage area M2 has an area M2-1 for storing the start address of each map block (see FIG. 3) at the beginning, and an area M2-2 for storing road data in each block. M2-3 ... has.

As shown in FIG. 6, the road data has a configuration in which data such as a direction is stored in association with the start point coordinates and the end point coordinates of the straight-line approximated road line segment li.

A concrete example is shown in FIG. 7 (a). Road data shows that the start points and end points (P ₀ , P ₀ ) of road line segments l ₁ , l ₂ , l ₃ are
₁ , P ₂ , P ₃ ) are stored and their orientations θ ₁ , θ are stored.
₂ , θ ₃ (other than θ ₁ not shown) are stored, and the line segment distance Δ
l ₁ , Δl ₂ , and Δl ₃ are defined by the difference between the start point and the end point coordinates.

Referring again to FIG. 4, the terrain (sea / river / railroad) data storage area M3 is an area for storing data relating to the sea, river, and railroad for route guidance.

The point (public facility or the like) data storage area M4 is an area for storing the current location of the public facility or the like for route guidance.

The character data storage area M5 is provided with the CR for route guidance.
An area for storing character display data at T19.

The area name retrieval data storage area M6 is an area for storing data for retrieving area names in units of municipalities, for area name retrieval in route guidance.

The position measurement processing in the vehicle route guidance device having the above configuration will be described with reference to FIGS. 7 (a), (b) and (c) with reference to FIGS. 8 and 9.

First, as shown in FIG. 8, the current position calculation process by GPS is started by a regular interruption every predetermined time ΔT.

When interrupted at regular intervals, in step 801, it is determined whether three or more GPS satellites can be received because two-dimensional positioning is performed.

If it is determined in step 801 that three or more GPS satellites cannot be received, the routine returns to step 801 after a predetermined time.

When it is determined in step 801 that three or more GPS satellites can be received, the process proceeds to step 802, and the current position (X _G , Y _G ) (for example, position P _{0 in} FIG. 7 (a)) and The DOP value at that time is calculated, and the process proceeds to step 803.

In step 803, it is determined whether the current mode is the departure place and the registration mode. The departure place registration mode is a mode provided for inputting initial conditions necessary for route guidance at the departure place, and the current position of the vehicle needs to be registered here.

When the registration mode of the departure place is determined in step 803, the process proceeds to step 804, where rewriting (registration) of the current location register is performed. Note that this registration may be manually input.

When it is determined in step 803 that the mode is not the starting value registration mode (running mode), the process proceeds to step 805.

In step 805, it is determined whether or not the DOP value is 10 or less. If the DOP value is 10 or less, it is determined that the positioning accuracy is good, and the process proceeds to step 806. However, if it is 10 or more, a predetermined time is waited and an interrupt return to step 801 is made. To do.

In step 806, the current position (X _G , Y _G ) measured by GPS in step 802 is stored in the stack area.

By the processing shown in FIG. 8 above, the departure value is registered in the current position register, and thereafter, the current position (X _G , Y _G ) by GPS is stored in the stack area.

Next, as shown in FIG. 9, the current position calculation process performed by the CPU 9 provided with the integral position measuring means 2 is step 901.
At 902, the starting point (X, Y) is read and the initial values are set, and then step 90 is executed by interruption at every constant distance ΔD.
It starts from 3.

The departure place read in step 901 is the current place (X _G , Y _G ) registered in step 804 shown in FIG.

The setting in step 902 is based on that the starting point is, for example, the position P ₀ shown in FIG. 7 (a) from the current position read in step 901, and the road data shown in FIG. The number of line segments cc (3 in the example of FIG. 7 (a)) and the distance Δlc of each line segment (Δl in the example of FIG. 7 (a))
₁ , Δl ₂ , Δl ₃ ) and the orientation of each line segment (θ ₁ , θ ₂ , θ _{3 in} the example of FIG. 7 (a)) are set as initial values.

Steps 903 and 904 show the processing for measuring the integrated position. The vehicle direction θ is read in step 903, and the integrated position is calculated in steps 904 and 905.

Step 906 is a process for calculating the traveling distance, in which the traveling distance ∫ΔD starting from the starting point and the traveling distance ∫ΔD ′ starting from the line segment starting point are calculated (see FIG. 7 (b)). To be done.

In step 907, the current position (x, y) and the travel distance ∫ △
D is transferred to the screen buffer, and the CRT 20 is caused to display the current position, traveling locus, and the like.

Step 908 shows processing for setting the variable C to 1. The variable C is for incrementing the line segment number CC set in the step 902 by one.

In steps 909, 910 and 911, it is detected which line segment lc the travel distance ∫ΔD 'from the starting point of the travel line segment corresponds to by incrementing the variable CC by one. Here, the line segment with the smallest distance is first detected.

When a line segment corresponding to the travel distance ∫ΔD 'is detected in step 909, the process proceeds to step 912.

In step 912, the GPS position data stored in the stack area in step 806 of FIG. 8 is taken out, and the process proceeds to step 913.

In step 913, the azimuth θ _G of the regression line L shown in FIG. 7C is calculated, and the process proceeds to step 914.

In step 914, the azimuth θ _G calculated in step 914 is compared with the azimuth θ _C set by the map data in step 902. If θ _C ≈θ _{C, the} next step 91
6. If not, the process proceeds to step 915.

In Step 915, the following calculation is performed, so that Step 9
The data fetched in 12 is stored again in the original stack area, and the process returns to step 910.

At step 916, the orientations θ _G and θ _C (for example, FIG.
Based on the θ ₁ ) match shown in (a), the line segment lc (for example, l
The end position of ₁ ) is confirmed, the traveling distance ∫ΔD 'is cleared to zero, and the process proceeds to step 917.

In step 917, the line segment end position (x
c, yc) (for example, P ₁ , (X ₁ , Y ₁ ), the current position (X, Y) is corrected, and this content is transferred to the screen buffer in step 918. The corrected position is the line segment that was run this time. The same is true at the end position and at the position of the starting point of the next running line segment.

Steps 919 and thereafter are for setting the required data for the next traveling line segment.

First, in step 919, the variable cc that defines the total number of adjacent nodes (the number of line segments) is cleared.

Next, in step 920, the start address of the road data shown in FIG. 6 is stored in the index register SI, and in steps 921, 922, 927, it is checked which of the start point and end point of each line segment matches the current position (x, y). If they match, another point (the end point if the start point or the start point if the end point) is entered in the distance calculation register in steps 923 and 924, the counter cc is incremented in step 925, and the line segment is calculated in step 926. The distance Δlc and the azimuth θ _C are obtained.

If the data end is confirmed in step 928, the process proceeds to step 903, and the current position correction process at the next line segment end position is performed in step 917 while performing the integration position display process in step 907.

As described above, in this example, the integrated position is displayed in the middle of the line segment, and the integrated position is corrected at the end position of the line segment with the map data. Therefore, the display position does not fly left and right on the road and a natural display is obtained. Done.

At this time, since the end position of the line segment is detected based on the current position obtained by GPS in the direction of the regression line shown in FIG. 7 (c), the corrected position becomes accurate and the map on which the traveling locus is displayed is displayed. Will almost overlap on the road.

In the embodiment shown above, the current position by GPS is not used for rewriting the current position register except for the measurement process in the registration mode of the departure place, but this is appropriately used for rewriting the current position register. However, the functions used may be combined. this is,
For example, it is useful when traveling on a road such as a mountain road that does not have road segment data as shown in FIGS. 5 and 6.

The present invention is not limited to the above-mentioned embodiments, but can be implemented in other modes by making appropriate design changes.

[Advantages of the Invention] As described above, according to the vehicle route guidance device of the present invention, it is possible to accurately perform position measurement and perform natural display.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of the present invention, FIGS. 2 to 9 show an embodiment of the present invention, FIG. 2 is a block diagram of a vehicle route guide device, and FIG. 3 is a block diagram. Explanatory diagram of map, FIG. 4 is a memory map of external memory, FIG. 5 is a memory map of road data, FIG. 6 is a data format of road data, and FIG. 7 (a), (b), (c) is FIG. 8 is an explanatory view showing an example of use of road data, FIG. 8 is a flowchart of a current position calculation process by GPS, and FIG. 9 is a flowchart of an integrated position calculation / correction process. 1 ... GPS position measuring means 2 ... integrated position measuring means 3 ... road data storage means 4 ... traveling line segment end position detecting means 5 ... current position correcting means 6 ... current position displaying means

Front page continuation (72) Inventor Katsuhiko Mizushima 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Akira Endo 2520, Takaba, Katsuta-shi, Ibaraki Hitachi Sawa Factory

Claims (1)

[Claims] 1. A direction detecting means for detecting a traveling direction of a vehicle, a distance detecting means for detecting a traveling distance of the vehicle, and a first current position calculating means for calculating a current position from the traveling direction and the traveling distance. Display means for displaying the current position calculated by the first current position calculating means, receiving means for receiving radio waves from GPS satellites, and current position of the vehicle from the radio waves received by the receiving means. Second current position calculation means for calculating, current position storage means for storing a plurality of current positions calculated by the second current position calculation means, and a plurality of current positions stored in the current position storage means A traveling direction calculation means for calculating the traveling direction of the vehicle, a road data storage means for storing the end point coordinates of each road line segment, the distance of each road line segment, and the direction of each road line segment, and detection by the distance detection means. Mileage Selecting means for selecting a traveling road line segment from the road data storage means according to the traveling azimuth calculated by the traveling azimuth calculating means, the distance of the road line segment selected by the selecting means, and the When the traveling distances detected by the distance detection means are compared and the end point of the road line segment is reached, the current position calculated by the first current position calculation means is set to the end point of the road line segment selected by the selection means. A vehicle route guidance device configured to include correction means for correcting coordinates.