JP3291929B2 - Vehicle navigation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular navigation apparatus for sequentially calculating the traveling position of a vehicle based on the detection outputs of a traveling distance detecting means and an azimuth detecting means mounted on the vehicle and displaying it on a map. In particular, the present invention relates to a vehicular navigation device that corrects a running position of a vehicle obtained by calculation based on position data of a verification point stored in a map storage unit.

[0002]

2. Description of the Related Art Conventionally, a running position of a vehicle is sequentially determined by calculation using respective detection outputs of running distance detecting means and azimuth detecting means mounted on a vehicle, and the calculated position of the vehicle thus obtained is calculated. 2. Description of the Related Art There is known a vehicular navigation device that points on a map displayed on a display device including a CRT, an LCD panel, and the like. However, in such a device, since each detection output by the traveling distance detection means and the azimuth detection means includes an error, it is necessary to avoid generating a certain error in the calculated position of the vehicle obtained by integrating the detection outputs. I can't.

In order to correct such an error, an apparatus for comparing the calculated position with a test point set on a map is known.
There is one disclosed in Japanese Patent No. 127113.

That is, in this device, a road is approximated by a polygonal line composed of a set of a plurality of unit straight line segments, and the end points of each unit straight line segment and intersections of roads are set as test points, and the positions of the test points are determined. It stores map information including data indicating data and data indicating connection relationships between test points. Then, based on a comparison between the calculated position of the vehicle and the data indicating the position of the verification point in the map information as described above, it is determined whether or not the vehicle has reached the target verification point, and the effect that the vehicle has reached the target verification point is determined. When the judgment is made, the calculation position is updated to the position of the target verification point, and the other verification points connected to the arrival verification point are determined as the next verification points that are closest to the traveling direction of the vehicle. Is to be selected. At this time, whether or not the vehicle has reached the target verification point is determined when the travel distance reaches the distance between the verification points obtained from the map information, and the calculation position is set to the predetermined verification point. The determination is made based on whether or not the error is within an error range. In this way, accumulation of errors is prevented by sequentially correcting the calculation position by comparison with the test point.

[0005]

However, the above-described conventional apparatus has the following problems when a plurality of test points exist in the same intersection. That is,
For example, when the map information includes an intersection A where five roads R1 to R5 intersect as shown in FIG. 9A, the intersection A includes, as shown in FIG. Road R1
Three test points Pa, Pb, and Pc are set so as to correspond to a road pattern passing through the center of R5. That is, in the map information, as shown by the solid line in FIG. 9B, the road patterns as shown in FIG. 9A are the verification points Pa to Pc in the intersection A and the roads R1 to Rc.
5, the segments S1 to S5 connected to the test points P1 to P5.
The intersection A is represented by a combination of S7, and the intersection A is configured as a composite intersection including the intra-intersection link composed of the adjacent segments S6 and S7.

In the example of FIG. 9, for example, when a vehicle traveling on the road R5 in the direction of the arrow x approaches the intersection A, it is determined that the vehicle has reached the verification point Pc. Other test points Pa, P4, P
Of the five, the one closest to the traveling direction of the vehicle is selected as the next target verification point. That is, when the vehicle turns left and enters the road R4, the verification point P4 is selected,
The verification point Pa is selected in each case where the vehicle travels in the directions of the other roads R1 to R3 (when the vehicle makes a U-turn, the verification point P5 is selected).

[0007] In this case, when the vehicle enters the road R4, the verification point P4 on the road R4 is selected without causing any problem.
Also when entering the vehicle, the traveling direction and the azimuth of the target verification point Pa almost coincide with each other, so that no major problem occurs.
However, when the vehicle goes straight on and enters the road R2, or when the vehicle turns left and enters the road R3, the traveling direction and the direction of the target verification point Pa are greatly displaced. It becomes possible. For this reason, it becomes impossible to match the road pattern on the map displayed on the display device with the vehicle traveling locus obtained by the calculation,
There is a problem that the display of the vehicle traveling locus departs from the road pattern.

[0008] As means for solving such a problem, a means described in Japanese Patent Application Laid-Open No. 4-269623 is conventionally known. That is, in the device described in this publication, when the vehicle reaches the verification point, when selecting the next target verification point, the vehicle is within a predetermined distance range from the verification point where the determination that the vehicle has passed was made. In addition to prohibiting the selection of a certain verification point, a verification point existing at a position exceeding the predetermined distance range from the verification point whose selection is prohibited is included in the target verification point selection target.

When such a configuration is applied to the examples of FIGS. 9A and 9B, when a vehicle traveling on the road R5 in the direction of the arrow x reaches the verification point Pc, the verification point Pc is set.
The selection of the test points Pa and Pb within a predetermined distance range from c is prohibited, and the test points P1 to P5 connected to the test points Pa to Pc are included in the target test point selection targets. Therefore, in this case, the road pattern as shown in FIG. 9A is a segment connected to the test point Pc and the test points P1 to P5 in the intersection A as shown by the solid line in FIG. The test points Pa and Pb in the intersection A are converted into a combination of S1 'to S5'.
(See FIG. 9B) will be skipped.

However, in the road pattern as shown in FIG.
Since c is regarded as the center of the intersection A, the deviation of the road pattern from the true center of the intersection A increases. Therefore, for example, when a vehicle traveling in the direction of the arrow x reaches the verification point Pc and turns left to enter the road R3, the vehicle must travel straight ahead for a predetermined distance after passing the verification point Pc and then turn left. Therefore, the traveling direction greatly deviates from the azimuth of the target verification point P3 which should be originally selected, and there is still a possibility that the tracking of the map information becomes impossible. Further, in order to perform the above-described conversion process (the process of skipping the verification point), every time the vehicle reaches the verification point, another verification point connected to the arrival verification point is set within a predetermined distance range. It is necessary to perform a process of checking whether or not there is, and there is a problem that a load for the check process increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to enable accurate tracking of map information even when a plurality of test points exist in the same intersection. An object of the present invention is to provide a vehicular navigation device having the following effects.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a mileage detecting means for detecting a mileage of a vehicle, an azimuth detecting means for detecting a heading of a vehicle, and setting on a road map. A map storage unit that stores map information including data indicating the positions of the plurality of test points and data indicating a connection relationship between the test points, based on each detection output by the traveling distance detection unit and the azimuth detection unit. Traveling position computing means for computing the traveling position of the vehicle, position displaying means for displaying the computed position by the traveling position computing means together with the map information, and comparing the computed position by the traveling position computing means with the map information. Based on this, it is determined that the vehicle has passed the verification point, and another verification point connected to the passage verification point is selected as a target verification point in the traveling direction of the vehicle. Verification point selecting means, and position correction means for correcting based on the position data of the verification point that the vehicle has passed the calculated position by the traveling position calculation means, the verification point selection means, If there are multiple test points in the same intersection,
The center of gravity position of those test points is calculated, the center of gravity position is subjected to a deformation process that is regarded as a single test point within the intersection, the passage of the single test point after the deformation process is determined, and the single test point is determined. The present invention is configured to select, from among other test points connected to a plurality of test points serving as a calculation reference, those present in the traveling direction of the vehicle as target test points (claim 1).

[0013] In this case, the map storage means is configured to store a flag in association with each data indicating a plurality of test points existing in the same intersection, and the test point selection means is changed to the test point selection means. It is also possible to adopt a configuration in which the deformation processing is performed when an associated verification point is selected (claim 2).

[0014]

According to the vehicle navigation apparatus having the structure described in the first aspect, the traveling position calculating means includes:
Traveling distance of the vehicle detected by the traveling distance detecting means,
The traveling position of the vehicle is calculated based on the traveling direction of the vehicle detected by the azimuth detecting means, and the position display means calculates the calculated position of the vehicle obtained by such a calculation.
The information is displayed together with the map information stored in the map storage means. The map information includes data indicating the positions of a plurality of test points set on the road map and data indicating the connection relationship between the test points. Based on the comparison with the above calculated position, it is determined that the vehicle has passed the verification point, and the other verification points connected to the passing verification point are located in the traveling direction of the vehicle. It will be selected as a test point. Further, at this time, the position correcting means corrects the calculated position by the running position calculating means as described above based on the position data of the verification point through which the vehicle has passed. In this way, each time the vehicle passes the target verification point, the calculation position is sequentially corrected, and among the other verification points connected to the passing verification point, the one corresponding to the traveling direction of the vehicle is changed to the next one. Select as target verification point.

In this case, the test point selecting means, when selecting the target test point as described above, when the test point to be selected is any of a plurality of test points existing within the same intersection. After performing a deformation process in which the center of gravity of the plurality of test points is calculated and the position of the center of gravity is regarded as a single test point within the intersection, the passage of the single test point after the deformation process is determined, and From among the other test points connected to the plurality of test points serving as the calculation reference of the single test point, the one existing in the traveling direction of the vehicle is selected as the target test point.

When such a transformation process is performed,
The road pattern centered on the intersection includes test points set on a plurality of roads intersecting the intersection (test points connected to the plurality of test points present in the intersection), and A single verification point is connected to each other. At this time, the single verification point is the position of the center of gravity of the plurality of verification points present in the same intersection, and is located at a position approximate to the true center of the intersection, and thus is obtained as described above. The deviation between the center of the road pattern (single verification point) and the true center of the intersection is reduced, and the deviation between the road pattern and the actual road pattern is also reduced.

For this reason, the deviation between the direction of the target verification point selected as described above in accordance with the determination of the passage of the single verification point and the traveling direction of the vehicle in the verification point selecting means is smaller than in the conventional configuration. Is sufficiently small, and as a result,
Even when a plurality of test points exist in the same intersection, the tracking of the map information can be accurately performed.

[0018] In the vehicle navigation apparatus having the structure described in claim 2, the map information stored in the map storage means is attached to each data indicating a plurality of test points existing in the same intersection. The test point selecting means automatically performs the above-described deformation processing when a test point accompanied by the flag is selected. Therefore, unlike the conventional configuration, every time the vehicle reaches the verification point, it is not necessary to perform a process of checking whether another verification point connected to the arrival verification point is within a predetermined distance range. Thus, the load for the checking process can be reduced.

[0019]

1 to 8 show an embodiment of the present invention.
This will be described with reference to FIG. In FIG. 4, which shows a schematic configuration of a vehicle navigation device, a vehicle speed sensor 1 is configured to detect a running speed of a vehicle based on, for example, rotation of wheels, and a microcomputer that detects a vehicle speed detected by the vehicle speed sensor 1 will be described later. By performing the integration process by using the number 10, the travel distance of the vehicle is obtained. Therefore, the vehicle speed sensor 1 constitutes a traveling distance detecting means according to the present invention. The azimuth sensor 2 is equivalent to azimuth detecting means for detecting the traveling azimuth of the vehicle, and includes known means such as a geomagnetic sensor, a vibration gyro, an optical fiber gyro, a gas rate gyro, a steering angle sensor, and the like. Available.

The map memory 3 as a map storage means stores C
The map memory 3 is constructed by combining a large-capacity storage medium such as a D-ROM and a drive device thereof. The map memory 3 corresponds to a predetermined range of a road map such as a prefecture unit or a Tokai region. The stored map information is stored. The map information includes road shape, road width, road name,
In addition to data for reproducing a road map including buildings, place names, terrain, etc., data indicating the positions of a plurality of test points set on the road map and data indicating the connection relationship between the test points are included. It has a configuration that includes it.

The test point data is data created based on a map or actual measurement in order to correct the traveling distance obtained from the vehicle speed sensor 1 and the traveling direction of the vehicle obtained from the direction sensor 2. In this embodiment, a road is approximated by a polygonal line composed of a set of a plurality of unit straight line segments, and the end points of each unit straight line segment and intersections of roads are set as test points. Points are set at predetermined intervals). And
The following data related to these test points is stored in the map memory 3 as map information.

Test point number unique to each test point Absolute position (longitude / latitude) of the test point Pi Area number including the test point (however, the area number is, for example, a section number when the whole of Japan is divided into a plurality of sections) ) Angle formed by unit straight line segments on both sides of the test point (curvature θ) The number i of other test points connected to the test point (i = 1 to 1)
m) The number Ni of another test point connected to the test point (the other test point was one of a plurality of test points constituting a link within an intersection in a complex intersection as described later) In this case, the link flag in the intersection is stored in association with the test point number Ni.) The distance to the other test point connected to the test point (Δ
i) Azimuth (αi) to another test point connected to the test point

The number Ni, distance Δi, and azimuth αi of the other test points in are determined by the number of other test points (i
= 1 to m). Also, the absolute position of the test point of
The test point distance of the test point is determined based on actual measurement or a map.

Here, the link flag within the intersection will be described. That is, in the map information corresponding to the road pattern as in the example of FIG.
The intersection A is configured as a complex intersection including an intra-intersection link composed of adjacent segments S6 and S7, as shown in FIG. 3B, and the number of another test point connected to the test point. When Ni corresponds to one of the plurality of test points forming the intra-intersection link, the intra-intersection link flag is stored in association with the number Ni of the relevant test point. Therefore, in the example of FIG.
The intra-intersection link flag is stored in association with the data of the other test point numbers Ni for .about.P5.

For example, in the case where the map information includes an intersection B where four roads R6 to R9 intersect with each other in a shifted state as shown in FIG.
As shown in FIG. 3B, two verification points Pd and Pe are set in such a manner as to correspond to a road pattern passing through the centers of the roads R6 to R9. That is, in the map information, the road pattern as shown in FIG. 8A is represented by the test points Pd and Pe in the intersection B and on the roads R6 to R9 as shown by solid lines in FIG. Verification point P6 ~
The intersection B is represented by a combination of the segments S8 to S12 connected to P9, and the intersection B is configured as a composite intersection including the intra-intersection link composed of the segment S12. Therefore, in the example of FIG.
The link flag within the intersection is stored in association with the data of the other test point number Ni related to P9.

On the other hand, the control switch 4 is operated by the driver to input an initial value, or a position display means such as a CR.
It is composed of various switches for selecting a map displayed at T5. Incidentally, the position display means may be constituted by an LCD panel.

The above-mentioned vehicle speed sensor 1, direction sensor 2, map memory 3, and control switch 4 are connected to the microcomputer 10. The microcomputer 10 is for realizing the functions of the traveling position calculating means, the verification point selecting means, and the position correcting means according to the present invention, and includes a CPU 11, a ROM 12, which stores control programs and data in advance, and a program. RAM 1 used for data storage and data transfer accompanying the execution of
3. It has a well-known configuration including an input / output circuit 14, a bus line 15 interconnecting them, and the like. The CPU 11 is used for transmitting signals from the vehicle speed sensor 1, the direction sensor 2, the map memory 3, the control switch 4 via the input / output circuit 14, control programs and data stored in the ROM 12, and data transfer with the RAM 13. The display content of the CRT 5 is determined based on the input / output circuit 14 and the CR.
This is performed through the T controller 6.

The CRT controller 6 decodes the map data transferred from the microcomputer 10 and reproduces the map data on the CRT 5 as a map screen. On the currently displayed map screen, for example, an arrow pointer indicating the traveling direction of the vehicle is displayed.

The microcomputer 10 may be provided in a fixed station without being mounted on the vehicle, and may be configured to transmit and receive data by an appropriate communication device to reproduce the position of the vehicle.

Next, with respect to the control contents of the microcomputer 10, only the parts related to the gist of the present invention will be described. That is, in FIG. 3 showing a flowchart relating to the calculation position correction processing, the microcomputer 10
Starts an operation when a power switch (not shown) is turned on, performs initialization processing for initializing associated registers and the like (step 101), and thereafter performs processing for setting an initial position of the vehicle at the start of traveling. Do (Step 10
2). In this embodiment, this setting process is performed when the occupant of the vehicle operates the control switch 4 to select a map displayed on the CRT 5 and instructs the vehicle position at this time on the map as an initial position. Shall be performed accordingly. However, in addition to this, the calculated position at the time of the end of the previous operation of the vehicle is E
The position may be stored in a nonvolatile memory such as an EPROM, and this position may be set as an initial position.

The microcomputer 10 displays the vehicle position (computed position) on the map screen of the CRT 5 as an arrow pointer. When the vehicle travels, the traveling of the vehicle output from the vehicle speed sensor 1 is performed. Based on the running distance obtained by integrating the speed and the traveling direction of the vehicle obtained from the direction sensor 2, the calculated running position of the vehicle is sequentially calculated, and based on the calculated position of the vehicle thus obtained. An interrupt display process of moving the position of the arrow pointer displayed on the map screen of the CRT 5 is performed.

When the initial position of the vehicle is set in step 102, a processing routine 103 for unifying links within the intersection is executed. The specific contents of this routine 103 are shown in the flowchart of FIG. It is shown.

That is, in the link-in-intersection single point processing routine shown in FIG. 2, first, the initial position is set as a temporary test point, and all the points within a predetermined distance range centered on the temporary test point are set. Data relating to the test point (each of the data as described above) is input (step 201), and it is determined whether or not the link flag within the intersection exists in the input data (step 202).

When the link flag within the intersection does not exist, the process returns as it is. When the link flag within the intersection exists, that is, at all the test points within a predetermined distance range centered on the temporary test point, this is returned. A plurality of test points connected to another test point (a test point within a predetermined distance range around the temporary test point may be applicable) constitutes a link within an intersection existing within the same intersection. If it is any of the above, data on all the test points constituting the link in the intersection is input (step 203).

Next, the center of gravity of the plurality of test points input in this way is calculated, and a deformation process is performed in which the position of the center of gravity is regarded as a single test point Pz in the intersection (step 204). Specifically, in the example of FIG. 9 described above, each coordinate data indicating the end point coordinates of the segments S6 and S7 constituting the intra-intersection link, that is, the positions of the test points Pa, Pb, and Pc within the intersection A are respectively shown in FIG. As shown in (xa, y
In the case of a), (xb, yb), and (xc, yc), the coordinates of the single test point Pz are obtained by the following equation.

[0036]

## EQU1 ## Pz (x, y) = ｛(xa, ya) + (xb,
yb) + (xc, yc)｝ / 3

After the execution of such a deformation process, a process is performed in which it is assumed that another test point connected to the intra-intersection link is connected to the single test point Pz (step 205). And return after this.

As a result of the execution of steps 203 to 205 as described above, the road pattern as shown in FIG. 9A becomes a single verification point in the intersection A as shown by a solid line in FIG. This is converted into a combination of segments S1 "to S5" connected between Pz and the test points P1 to P5, respectively. As shown by the solid line in FIG. 8C, a road pattern as shown in FIG. 8A has a single test point Pz (test points Pd, Pe (see FIG. 8B)) within the intersection B.
Is converted into a combination of segments S8 'to S11' connected between the test points P6 to P9, respectively.

Referring back to FIG. 3, after executing the intra-intersection link single point processing routine 103, a verification point to which the vehicle is heading is searched and selected from the verification point data input as described above (step). 104). In this step 104, among the test points in the traveling direction of the vehicle obtained from the output of the direction sensor 2, the closest one is selected as the initial target test point. Instead of the plurality of test points constituting the inner link, a single test point Pz deformed as described above is included.

Next, the distance d from the temporary verification point (the initial position set in step 102) to the initial target verification point
Is calculated (step 105). Hereafter, this step 1
At 05, the distance d is obtained by searching the test point data for the distance Δi between the test point at which the vehicle has passed and the target test point selected after passing.

Subsequently, the radius r of the test circle is calculated (step 106). Here, as shown in an example in FIG. 5, the test circle radius r is calculated so as to gradually increase with an increase in the accumulated traveling distance, and each time the vehicle turns right or left at an intersection or passes a bending point. , The integrated travel distance as a reference for the calculation of the test circle radius r is started to be integrated from the initial value. In particular,
In this embodiment, the radius r of the test circle is calculated by the following equation.

[0042]

## EQU2 ## where, K1, K2: constant (K1> K2) d: distance between test points Σd: distance from test point of intersection or inflection point ro: initial value (minimum test Circle radius)

Next, it is determined whether or not the initial target verification point (target verification point) is an intersection or an inflection point (step 1).
07). If "NO" is determined here, that is, if the target verification point is a point on one road, step 108
Execute the following processing.

In step 108, the position Q and the traveling distance D of the vehicle are calculated by integration from the above-mentioned provisional verification point (initial position) or the verification point passed last time. Next, it is determined whether or not the travel distance D is equal to or longer than the test point distance d calculated in step 105 (step 109), and steps 108 and 109 are repeatedly executed until the relation of D ≧ d is satisfied. Thereafter, when the traveling distance D becomes equal to or longer than the verification point distance d,
The position Q of the vehicle at the time when D = d is calculated (step 110), and it is determined whether or not the calculated position Q is within the test circle of the target test point (step 111).

If "YES" is determined in the step 111, that is, if the calculation position Q is within the test circle of the target verification point, it is regarded that the vehicle has passed the target verification point and the calculation position Q is set to the target verification point. A pull-in processing routine 112 for updating to the verification point is executed. Therefore, the subsequent calculation position Q is obtained based on this target verification point. For example, when the vehicle travels straight from the initial position on the road as shown in FIG. 5 and then turns right at the intersection C and travels in the direction of the intersection D, the pull-in process is performed at the verification points P21, P22, P23, and P25.

After the execution of the pull-in process, the link-in-intersection single point processing routine 113 having the contents shown in FIG. 1 is executed. This routine 113 is basically the same as the above-mentioned intra-intersection link single point processing routine 103 shown in FIG.

That is, in the link-in-intersection one-point processing routine shown in FIG. 1, first, data relating to another test point connected to the passing test point is input (step 301), and the input data is included in the input data. It is determined whether an intra-intersection link flag exists (step 302).

If the link flag within the intersection does not exist, the process returns as it is. However, if the link flag within the intersection exists, that is, if another test point connected to the pass verification point exists within the same intersection. If it is any of the plurality of test points forming the inner link, data relating to all test points forming the inner link of the intersection is input (step 303).

Subsequently, the process of calculating the center of gravity of the plurality of test points input in this way and considering the position of the center of gravity as a single test point Pz in the intersection is performed in the same manner as in step 204 shown in FIG. (Step 304), and after the execution of such a deformation process, a process is executed for assuming that the other test points connected to the intra-intersection link are connected to the single test point Pz. (Step 30
5), then return.

Therefore, steps 303 to 30
5 is executed, the road patterns as shown in FIGS. 9A and 8A are converted as shown by solid lines in FIGS. 9D and 8C, respectively. become.

Returning to FIG. 3, after the execution of the link-in-intersection single point processing routine 113, the test point to which the vehicle is heading is searched and selected from the test point data input as described above (step). 114). In this step 114, among the verification points in the traveling direction of the vehicle obtained from the output of the direction sensor 2, the one closest to the traveling direction of the vehicle is selected as the initial target verification point. The target includes a single verification point Pz deformed as described above in place of the plurality of verification points forming the intra-intersection link.

On the other hand, if "NO" is determined in the step 111, it is assumed that the vehicle is traveling on a road or a parking lot which is not included in the map information. After executing the correction processing routine 115 for drawing the calculation position Q of the vehicle to the nearest verification point, the control after the above-mentioned intersection single point processing routine 113 is executed.

In step 107, "YE
If "S" is determined, that is, if the target verification point is determined to be an intersection or an inflection point, the control after step 116 is executed.

In step 116, the aforementioned step 10
As in the case of 8, the position Q and the traveling distance D of the vehicle are calculated. Then, in steps 117 to 119, the accumulated traveling distance D from the provisional verification point (initial position) or the verification point passed last time is calculated.
Is greater than or equal to the difference (d−r) between the test point distance d calculated in step 105 and the test circle radius r, and the sum (d + r) thereof
For example, as shown in FIG. 6, a straight line connecting the last calculated position Qn-2 and the previous calculated position Qn-1 and a previous calculated position Qn-1 and the current calculated position Qn are defined as shown in FIG. The operation for obtaining the curvature θn-1 which is the angle between the straight line and the connecting straight line is repeated.

When the traveling distance D becomes equal to or more than (d + r), the one indicating the maximum value of the curvature θn-1 calculated in the loop processing of the above-mentioned steps 116 to 119 and the calculation position Q at that time are set to the maximum. Curvature θmax and maximum curvature point Pma
It is calculated as x (step 120).

Next, it is determined whether or not the maximum curvature θmax is larger than a predetermined value θr (step 121), and θmax ≦ θr
In the case of, the control after step 110 described above is executed. That is, the maximum curvature θmax is equal to the predetermined value θr (for example, 20
In the following cases, it means that the vehicle goes straight ahead at the intersection or turns at the curve at the inflection point using the full width of the road and shifts to the same processing as a straight road.

If "YES" is determined in the step 121, it is determined whether or not the maximum curvature point Pmax is within the test circle of the target test point (step 122). If it is not within the test circle, the process proceeds to the correction processing routine 115. If it is within the test circle, the position of the maximum curvature point Pmax is set as the position of the target test point.
In this case, the pull-in process is performed at the test points P24 and P26 in the example of FIG.

As described above, the calculation position Q of the vehicle is corrected, whereby the position of the arrow pointer displayed on the map screen of the CRT 5 by the above-described interrupt display processing is determined by the vehicle's verification point. Is corrected successively each time an error occurs.

In the above-described embodiment, the microcomputer 10 executes the intra-intersection link single point processing routine 103 or 113 at the beginning of the running of the vehicle and each time the vehicle reaches the target verification point. When selecting a target verification point by using, if the verification point to be selected is any of a plurality of verification points forming a link in an intersection within a complex intersection, the centroid position of the plurality of verification points is determined. The calculation is performed to perform a deformation process in which the position of the center of gravity is regarded as a single verification point Pz in the composite intersection, and the single verification point Pz is included in a target verification point selection target.

When such a deformation process is performed,
The road pattern centering on the composite intersection includes test points set on a plurality of roads intersecting the intersection (test points connected to the plurality of test points existing in the intersection). The single verification point Pz is connected to each other (see FIGS. 9D and 8C).

At this time, the single verification point Pz is the position of the center of gravity of a plurality of verification points existing in the same intersection, and is located at a position approximate to the true center of the intersection. The deviation between the center of the obtained road pattern (single verification point Pz) and the true center of the intersection is reduced, and the deviation between the road pattern and the actual road pattern is also reduced.

As a result, when the single verification point Pz as described above is selected as the target verification point, the single verification point Pz is selected.
the azimuth of the target verification point selected in accordance with the determination of the passage of z,
As a result, the deviation from the traveling direction of the vehicle does not increase as in the conventional configuration. As a result, even when the vehicle passes through a complex intersection including an intra-intersection link composed of a plurality of verification points, the map information can be obtained. Tracking can be performed accurately.

In addition, the other test point is added to “the number Ni of another test point connected to the test point” in the test point data stored in the map memory 3 and the other test point in the composite intersection is added. If it is one of the plurality of test points forming the link within the intersection, the link flag within the intersection is stored, and the link flag within the intersection is determined by the link within the intersection processing routines 103 and 113. Only when the associated verification point is selected, the arithmetic processing for calculating the single verification point Pz is automatically performed. Therefore, each time the vehicle reaches the verification point, as in the conventional configuration, There is no need to perform a complicated process of checking whether or not another test point connected to the arrival test point is within a predetermined distance range, and there is an advantage that the burden of the check process can be reduced.

Note that the present invention is not limited to the above-described embodiment, and the following modifications or extensions are possible. Although the link flag in the intersection is stored in association with “the number Ni of other test points connected to the test point” in the test point data, it is attached to the “test point number” in the test point data. In this case, the link flag in the intersection may be stored. In this case, when the test point specified by the test point number accompanied by the link flag in the intersection is selected as the target test point, the above-described single point is used. Verification point Pz
Is calculated. Also, in the map information,
The configuration may include data representing a straight line segment connecting the test points. In this case, a link flag within an intersection may be stored in association with the straight line segment data.

[Brief description of the drawings]

FIG. 1 is a flowchart showing control contents by a microcomputer according to an embodiment of the present invention;

FIG. 2 is a flowchart showing the contents of control by a microcomputer;

FIG. 3 is a flowchart showing the contents of control by the microcomputer;

FIG. 4 is a diagram schematically showing the entire hardware configuration.

FIG. 5 is a view showing an example of a road pattern for explaining a calculation position correction process of a vehicle;

FIG. 6 is a conceptual diagram for explaining an operation for obtaining a curvature at a calculation position of a vehicle.

FIG. 7 is a diagram for explaining an example of calculating a center of gravity position of a test point;

FIG. 8 is a view for explaining an example of a road pattern;

FIG. 9 is a diagram for explaining a road pattern example 2

[Explanation of symbols]

In the drawings, 1 is a vehicle speed sensor (travel distance detecting means), 2 is a direction sensor (direction detecting means), 3 is a map memory (map storage means), 5 is a CRT (position display means), 10 is a microcomputer (travel position). Calculation means), test point selection means,
Position correcting means).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-141613 (JP, A) JP-A-2-151714 (JP, A) JP-A-5-297802 (JP, A) JP-A-63- 127113 (JP, A) JP-A-4-269623 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21/00-21/36 G08G 1/0969 G09B 29/00- 29/10

Claims (2)

(57) [Claims] 1. A traveling distance detecting means for detecting a traveling distance of a vehicle, an azimuth detecting means for detecting a traveling azimuth of a vehicle, data indicating positions of a plurality of test points set on a road map, and each test point. Map storage means for storing map information including data indicating a connection relationship between the two, and travel position calculation means for calculating a travel position of the vehicle based on each detection output by the travel distance detection means and the direction detection means; and Position display means for displaying the calculated position by the running position calculating means together with the map information; and determining that the vehicle has passed the verification point based on a comparison between the calculated position by the running position calculating means and the map information. A test point selecting means for selecting, as a target test point, a test point existing in the traveling direction of the vehicle from among other test points connected to the passing test point; And a position correcting means for correcting the calculated position based on the position data of the verification point that the vehicle has passed, wherein the verification point selecting means is provided when a plurality of verification points exist in the same intersection. Calculates the centroid position of those test points, performs a deformation process in which the position of the center of gravity is regarded as a single test point within the intersection, determines the passage of the single test point after the deformation process, and performs the single test For a vehicle characterized in that it is configured to select, as a target verification point, one existing in the traveling direction of the vehicle from among other verification points connected to a plurality of verification points serving as a point calculation reference. Navigation device. 2. The map storage means stores a flag in association with each data indicating a plurality of test points present in the same intersection, and the test point selecting means includes a test point with the flag. 2. The vehicle navigation device according to claim 1, wherein the transformation processing is performed when is selected.