JPH0829189A - Apparatus for estimating running position of vehicle - Google Patents

Abstract

PURPOSE:To prevent an erroneous estimation as much as possible by removing unsuitable roads for every group of proposed roads of a branch relationship by a deleting means through relative comparison. CONSTITUTION:A current position is calculated by an electronic control circuit 20 on the basis of a running distance detected by a vehicle speed sensor 1 and a running direction from a direction sensor 2, and also a running track of a vehicle is obtained. The position and the track are stored in a RAM 26. A proposed road pattern for the current running direction of the vehicle is selected and registered in the RAM 26. A correlation value and a probability indicating an approximately degree are calculated for every proposed road. On the basis of the correlation value and the probability, unsuitable roads are deleted from the proposed roads. Unsuitable roads are first deleted in a branch group, and then the deletion process is carried out for all of the proposed roads. Thereafter, those roads outside an estimated position are deleted. After the deletion operation, a total probability is evaluated and a road of the highest evaluation is selected among the whole of the proposed roads.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle traveling position estimating device, and more particularly to a vehicle traveling position estimating device for comparing a traveling locus with road pattern data to estimate a current position.

[0002]

2. Description of the Related Art Conventionally, a vehicle position is calculated by obtaining a traveling direction and a traveling distance of a vehicle on the basis of detection signals from sensors such as a direction detecting means and a traveling distance detecting means mounted on a vehicle, It is known to display the position of a vehicle on a map displayed on a display based on the calculated position. However, since the detection values of the traveling distance detection means and the direction detection means include some errors, the calculated position of the vehicle obtained by integrating these detection values has an error. Even in a GPS system using an artificial satellite, these errors may cause an error in the measurement data when there is a building between the artificial satellite and the vehicle.

In order to correct such an error, the calculated vehicle trajectory is compared with the road pattern of the candidate road extracted as a candidate from the map data, and the degree of coincidence (approximation degree) determines that the candidate road A device for estimating which road the vehicle is traveling is known, and is disclosed in, for example, Japanese Patent Laid-Open No. Hei 2
It is disclosed in Japanese Patent Publication No. 130415.

When the candidate roads are branched due to the progress of the vehicle, the candidate roads are increased one after another, which causes problems such as insufficient memory on the device side and increased pattern matching load. Therefore, in the above-mentioned conventional technique, at the time of branching a candidate road, the candidate roads having the highest possibility of traveling are narrowed down.

[0005]

However, in the above-mentioned conventional technique, when a branch occurs, the number is always narrowed down to one.
Since the number of candidate roads is prevented from increasing, if the correct road is excluded by the single erroneous estimation at that time, the estimation process will be performed in the subsequent process with the correct road excluded. Therefore, even if the burden of matching the devices is reduced, there is a high possibility that the wrong road will be continuously estimated, and there is a problem as a vehicle traveling position estimation device aiming at accurate display.

The present invention intends to prevent such an erroneous estimation as much as possible and to solve the shortage of memory and the increase in the load of pattern matching by appropriately excluding the candidate roads that have branched.

[0007]

According to the first aspect of the present invention,
As illustrated in FIG. 11, a vehicle running locus detecting means,
Candidate roads are extracted from the map information storage means and roads near the vehicle stored in the map information storage means, and the road patterns of the candidate roads are compared with the travel loci detected by the travel locus detection means. Estimating means for estimating the traveling path by
In a vehicle traveling position estimation device including a candidate road deleting unit that deletes an inappropriate road as a candidate from the candidate road based on a result of comparison between the traveling locus and the road pattern, the candidate road further branches. Every time the branch relationship is stored, the branch relationship storage means for storing the branch relationship and the branch relationship stored by the branch relationship storage means are used as candidates by a relative comparison for each group of candidate roads having the branch relationship. A vehicle traveling position estimating device, comprising: a branch deleting unit that deletes an appropriate road.

The invention according to claim 2 is, as illustrated in FIG. 12, stored in the vehicle running locus detection means, the vehicle position / direction estimation means, the map information storage means, and the map information storage means. Estimating means for extracting a candidate road from roads near the vehicle and comparing the road pattern of the candidate road with the traveling locus detected by the traveling locus detecting means to estimate a traveling road; the traveling locus and the road; Based on a comparison with the pattern and a comparison between the position / direction of the vehicle estimated by the position / direction estimation means and the road position / direction,
In a vehicle traveling position estimation device including a candidate road deleting unit that deletes an inappropriate road as a candidate from the candidate road, a branching relation storing unit that stores the branching relation every time the candidate road branches. A branch-inside deleting means for deleting an inappropriate road as a candidate by relative comparison for each group of candidate roads having a branching relationship based on the branching relationship stored by the branching relationship storing means. It is a vehicle traveling position estimation device characterized by the above.

According to a third aspect of the present invention, in the vehicle traveling position estimating apparatus according to the first or second aspect, the in-branch deleting means deletes under a condition that is easier to delete than the deleting process executed by the candidate road deleting means. is there. In the invention according to claim 4, the comparison between the traveling locus and the road pattern in the candidate road deleting means finds the degree of approximation of the pattern by pattern matching between the traveling locus and the road pattern, and is the highest among them. It is a process of deleting a road having a degree of approximation lower than a degree of approximation from the candidate road by the in-branch deleting means, for each group of candidate roads having a branching relationship, with the predetermined value being a smaller value. The vehicle traveling position estimating device according to claim 3, wherein a road having a degree of approximation lower than a highest degree of approximation by a predetermined value or more is deleted from the candidate roads.

According to a fifth aspect of the present invention, the vehicle traveling position estimation according to any one of the first to fourth aspects, wherein the in-branch deleting means performs deletion processing before the deletion processing executed by the candidate road deleting means. It is a device.

[0011]

According to the first and second aspects of the invention, the in-branch deleting means eliminates inappropriate candidates as relative candidates for each group of candidate roads having a branching relationship. Here, the relative comparison is to compare a relative difference between the candidate roads in the group, that is, a relative difference in aptitude as a candidate.

For this reason, candidates having a relatively high suitability are retained, and candidates having a relatively low suitability are deleted. In this way, only inappropriate candidate roads are excluded, not necessarily one. In addition, since the branch relation is stored and held, it is not necessary to narrow it down to one at a time immediately after branching, and there is a possibility that it is an inappropriate road in each branch relation while referring to the stored branch relation. Only after the road has risen sufficiently can the relevant road be eliminated.
Therefore, as always, always 1 at a time immediately after branching.
It is possible to reduce the possibility of erroneous estimation due to narrowing down to one.

Further, if there is an inappropriate one as a whole, the candidate road deleting means compares the traveling locus with the road pattern, and in claim 2, the position / direction of the vehicle further estimated and the road Since the deletion is performed based on the comparison result with the position / direction, even if the candidate road is branched, regardless of that, the inappropriate road is simply deleted from the candidate road as a candidate. Therefore, even if the candidate roads left by the deletion by the in-branch deleting means are truly inappropriate, they are always excluded.

Therefore, it is possible to prevent erroneous estimation as much as possible, and it is possible to prevent a memory shortage by appropriately removing the candidate roads from the candidate roads by the deletion processing of the in-branch deleting means and the candidate road deleting means. The increase can be prevented. The deletion process in the in-branch deletion unit may be deleted under a condition that is easier to delete than the deletion process executed by the candidate road deletion unit. That is, in the group of candidate roads having a branching relationship, the inadequacy is clearly expressed even if the difference between the candidate roads having no branching relationship is relatively small. Therefore, inappropriate candidate roads can be deleted early, and the memory shortage and the pattern matching load can be prevented earlier.

For example, in the comparison of the traveling locus and the road pattern in the candidate road deleting means, the pattern approximation is obtained by pattern matching between the traveling locus and the road pattern. Is a process of deleting a road having a degree of approximation lower than a predetermined value from the candidate roads, and the inside-branch deleting means sets the predetermined value to a smaller value, for each group of candidate roads having a branching relationship. A road having a degree of approximation lower than the highest degree of approximation by a predetermined value or more may be deleted from the candidate roads. Since the predetermined value in the in-branch deleting means is smaller than the predetermined value in the candidate road deleting means, even if there is a difference in the degree of approximation that cannot be deleted in the candidate road deleting means, it is deleted in the in-branch deleting means. Because.

Further, since the deletion processing by the candidate road deletion means and the deletion processing by the intra-branch deletion means are normally repeated, any deletion processing may be performed first in each control cycle. The effect of preventing erroneous estimation, preventing memory shortage, and reducing the burden of matching processing due to deletion of candidate roads by the deletion processing by the internal deletion means occurs.

In particular, as described above, in the case where the deletion processing in the branch deletion means is deleted under a condition that is easier to delete than the deletion processing executed by the candidate road deletion means, the deletion in branch is performed in each control cycle. The deletion process by means,
By prioritizing the deletion processing by the candidate road deletion means, the load of the deletion processing by the candidate road deletion means can be reduced one control cycle earlier.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a vehicle traveling position display device. The vehicle has a vehicle speed sensor 1 and a direction sensor 2 mounted thereon, and the vehicle speed sensor 1 detects a running speed of the vehicle. The traveling distance of the vehicle is obtained by integrating the traveling speed by the electronic control circuit 20 described later. The azimuth sensor 2 detects the traveling direction of the vehicle, and in the present embodiment, the azimuth sensor 2 is used to detect the geomagnetism to obtain the direction. However, the azimuth sensor 2 may be a gyro compass or one that accumulates steering angles of the vehicle obtained from the difference in rotation between the left and right steered wheels to obtain the direction. Of course, a GPS system may be used as a device for directly detecting the position.

A map memory 4 is also provided, which is composed of a large-capacity storage device such as a compact disk. The map memory 4 stores map data of a predetermined range such as Tokyo, Aichi prefecture or Tokai region. The map data is data for reproducing a map such as road number, road type, road shape, road width, road name, building, place name, and topography. Of these, the road shape data is road pattern data that is created based on map data or actual measurement in order to be compared with the vehicle travel locus and correct the travel position.

Further, a control switch 6 is provided, which is a switch for the driver to input an initial value, select a map to be displayed, or set a route to a destination. It is configured. The vehicle speed sensor 1, the direction sensor 2, the map memory 4, and the control switch 6 are connected to the electronic control circuit 20, respectively. This electronic control circuit 20 is a well-known CPU 2
2. R in which control programs and data are stored in advance
The OM 24, the readable / writable RAM 26, and the input / output circuit 2
8 are connected to each other via a common bus 30. The CPU 22 includes a vehicle speed sensor 1, a direction sensor 2,
The signals from the map memory 4 and the control switch 6 are input via the input / output circuit 28, and these signals are stored in the ROM 2
4. Based on programs and data in RAM26,
CR via input / output circuit 28 and CRT controller 32
The drive signal is output to T34.

The CRT controller 32 is a CRT 3
4 is controlled, the map data transferred from the electronic control circuit 20 is reproduced as a map on the screen of the CRT 34, and the calculated position of the vehicle transferred from the electronic control circuit 20 is displayed on the currently displayed map. It has a configuration to display.

It should be noted that the electronic control circuit 20 may be configured not to be mounted on a vehicle but to be provided on a fixed station and transmit / receive data by an appropriate communication device to reproduce the vehicle position. In the electronic control circuit 20, when a power switch (not shown) is turned on, the CPU 22 starts execution of arithmetic processing according to a program preset in the ROM 24.

In this embodiment, the vehicle occupant operates the control switch 6 to select a map displayed on the CRT 34 before starting the vehicle, and indicates the vehicle position on the map as the initial position. Alternatively, in addition to this, the calculation position at the time of the previous stop of the vehicle may be stored in the non-volatile memory and this position may be set as the initial position.

When the vehicle starts traveling, the traveling distance obtained by integrating the traveling speed input from the vehicle speed sensor 1 and the traveling direction obtained from the azimuth sensor 2 are detected. When the vehicle travels a certain distance, the current calculated position calculated based on the detected traveling distance and traveling direction is CR.
It is displayed on the map of T34. Furthermore, the traveling locus of the vehicle is obtained by accumulating the calculated positions, and the road position is estimated by comparing with the road pattern data in the vicinity of the calculated positions to correct the display position. .

Next, the road estimation process performed by the electronic control circuit 20 will be described with reference to the flowchart shown in FIG. Although not shown, the current position is calculated at a predetermined timing based on the traveling distance obtained by integrating the traveling speed input from the vehicle speed sensor 1 and the traveling direction obtained from the azimuth sensor 2 by another dead reckoning process. The traveling locus of the vehicle is also obtained by accumulating a predetermined number of the current positions.

First, when the processing is started, the traveling locus that has already been obtained is stored in a predetermined work area of the RAM 26 (step 101). Next, the current vehicle speed is also stored in the same work area (step 103). Next, map memory 4
Road pattern data in the vicinity of the above running locus (for example, within a predetermined radius from the current position of the vehicle: within a circle indicated by a dashed line in FIGS. 5 to 7 described later) is extracted from the The road pattern running 60 ° to the left and right with respect to the traveling direction is selected as a candidate road pattern and registered in a predetermined storage area of the RAM 26 (step 104).

For example, as shown in FIG. 5A, it is assumed that three roads R0, R1 and R2 are selected as candidate roads. The arrow in the center of the circle indicated by the alternate long and short dash line indicates the vehicle position obtained by the dead reckoning described above, the direction of the arrow indicates the traveling direction of the vehicle, and the range of the circle indicated by the alternate long and short dashed line indicates the error range of the vehicle position. There is.

The contents of the storage area 26a in this state are shown in FIG.
(A). The storage area 26a includes the candidate roads R0 and R0.
It is provided for each R1 and R2, and stores a road number, a correlation value described later, a probability described later, and other data for each area. In step 104, when there is a branch of the candidate road, a branch history described later is also registered in the predetermined storage area.

Next, the correlation value representing the degree of approximation is calculated for each candidate road (step 105). This calculation starts from the intersection of the candidate road pattern with a perpendicular line from the vehicle position, and varies depending on the traveling speed.
The travel path of 10m obtained every 0m travel is 500m
Pattern matching is performed on the candidate road pattern for 50 minutes, that is, 50 correlation values obtained are averaged to obtain the correlation value of the corresponding candidate road.

The correlation value is obtained, for example, by sequentially calculating the deviation between the traveling locus and the candidate road pattern from one end point to the other end point at a predetermined interval by the least squares method.
Further, as shown in Japanese Patent Laid-Open No. 2-138813,
When the vehicle running trajectory and the road pattern are each approximated to a polygonal line using a unit length vector, and when the two are superposed so that the beginnings of the approximated polygonal lines match, The sum total may be used as the correlation value. Also in this embodiment, the larger the value, the lower the correlation, that is, the approximation is not performed. This correlation value is stored in the storage area 26a of the corresponding candidate road.

Next, the accuracy is calculated (step 10).
7). Here, when the high-speed state of the vehicle continues for a predetermined distance or more, a process of setting the accuracy on the highway among the candidate roads is performed. This processing is also performed for each candidate road and is stored in the storage area 26a of the corresponding candidate road.

Next, on the basis of the correlation value and the accuracy calculated in this way, the process of deleting the roads listed as candidates is performed (step 108). This is the process of deleting roads that are inappropriate as candidates from the candidate roads.
Details are shown in FIG. First, deletion processing within the branch group is performed (step 200). A branch group is a group of roads that branch from the same road when a candidate road branches during running, and branch history data indicating the branch relationship is stored in a predetermined storage area of the RAM 26. ing. In the case of FIG. 5 (a), the vehicle has just started to travel and the branch history data has not been formed.

FIG. 4 shows details of the deletion processing within the branch group. First, the presence of a branch history is determined (step 210). If it does not exist, a negative determination is made and processing proceeds to the next processing. In the case of FIG. 5A, since the branch history data does not exist by chance, other processing is not performed here.

Consider a case where the road R3, which is a branch of the candidate road R0, is selected as the candidate road by the traveling of the vehicle as shown in FIG. 5B. In this case, the road R3 is added to the storage area 26a in step 104 as shown in FIG. 9B. At the same time, as shown in FIG. 10A, a 16-bit area (numbering in hexadecimal) is secured in the branch history storage area 26b, and "1" is written in the bit position of the corresponding candidate road. It That is, the candidate road R
“1” is entered in the 0th digit representing 0 and the 3rd digit representing the candidate road R3. In addition, in FIG. 10, among the bit positions,
"0" is entered in the blank part.

Therefore, this branch history storage area 26
If b is secured, an affirmative decision is made in step 210 of FIG. 4, and it is then decided whether or not there is unprocessed branch history data (step 220). Since the branch history data of FIG. 10A exists, the processing of the branch history data is performed.

First, the total accuracy is read for each candidate road registered in the branch history data (step 230). The overall accuracy is the total of the correlation value in step 105 and the accuracy in step 107, and the overall accuracy is calculated by the following equation 1.

[0037]

[Equation 1]

Here, AP is the overall accuracy, C is the correlation value, and P is the accuracy. Next, the data of this total accuracy is sorted (step 240). This sort is done in ascending order of value. The road with the lowest value at the beginning of the sorted data is the road with the highest evaluation in the branch group, that is, the road that is most likely to be traveling in the branch group.

Next, the level of overall accuracy is checked. For example, if the total accuracy of the sorted first candidate road is checked and the value is higher than a predetermined reference value,
There is no big difference when compared with other candidate roads in the same branch history,
Since it does not serve as a reference for deleting the candidate road, the process returns to step 220 again to move to the next branch history process.

If the total accuracy of the sorted leading candidate roads is lower than a predetermined reference value, the relative accuracy of each branch group is compared and deletion processing is performed according to the comparison result. become. That is, the difference between the overall accuracy of the first candidate road and the overall accuracy of the second and subsequent candidate roads is calculated. If the difference is larger than a predetermined value, the second and subsequent relevant candidate roads from the candidate road are selected. A process of deleting is performed (step 260). For example, the overall accuracy is 0
If it is set between 255 and 255, the second and subsequent candidate roads are to be deleted when the following expression 2 is satisfied.

[0041]

[Equation 2]

Here, APX0 represents the overall accuracy of the first candidate road, and APXn represents the overall accuracy of the second and subsequent candidate roads. Instead of Equation 2, for example, as in Equation 3 below,
You may judge by a multiple. For example, if the total accuracy of the first candidate road is twice or more, the second and subsequent candidate roads may be deleted.

[0043]

(Equation 3)

For example, by checking the branch history in the state of FIG. 5B, even if the total accuracy AP3 of the candidate road R3 is larger than the total accuracy AP0 of the candidate road R0, AP3
If −AP0 ≦ 15, the road R3 is not deleted from the candidate roads. Further, as the vehicle runs, FIG. 6 (c)
When the state of (3) is reached, it is assumed that the overall accuracy AP3 is increased for the candidate road R3 because the correlation value C is particularly large. AP3-AP0 in the process of step 260
> 15 and road R3 is deleted from the candidate roads. That is, as shown in FIG. 9C, the area R3 is deleted from the content of the storage area 26a. Also, the third digit "1" in the branch history data shown in FIG. 10A is set to "0".
At this time, since the branch history data is "0" only at the 0th digit, at step 260, as shown in FIG.
The branch history data of (a) is also deleted.

Delete processing within branch group (step 20)
When 0) ends, a deletion process for all candidate roads is executed next (step 300). Here, all candidate roads are sorted by the total accuracy, and the difference between the total accuracy AP0 of the sorted first candidate road and the total accuracy APn of the second and subsequent candidate roads is calculated, and the difference is a predetermined value (step 26
If it is larger than a predetermined value larger than the predetermined value of 0), a process of deleting from the candidate road is performed. For example, assuming that the total accuracy is set between 0 and 255, the second and subsequent candidate roads are to be deleted if the following expression 4 in which the predetermined value is "31" is satisfied.

[0046]

[Equation 4]

Since the predetermined value is "31" in the equation 4 and the predetermined value is "15" in the equation 2, the deletion in step 300 is performed on a looser basis than the deletion in step 260. That is, it is more difficult to delete than in step 260. In this case as well, the determination may be made by a multiple as shown in the following Expression 5. Here, the deletion is determined based on whether or not it is "3" times or more, which is larger than the case of Expression 3.

[0048]

(Equation 5)

Next, for roads that are off the estimated position,
Deletion processing is performed (step 400). That is, FIG.
If the vehicle position is outside the error range of the vehicle position indicated by the dashed-dotted line circle in 7, the candidate is deleted. In this way, the deletion process (step 108) is completed, and then the overall accuracy obtained by the equation 1 is evaluated. Among all the candidate roads, the road having the highest evaluation (here, the value of the overall accuracy is the highest). (Low road), that is, the road that is most likely to be currently traveling is selected (step 109). For example, in the situation of FIG. 6C, the mark of the current position is displayed on the candidate road R1.

Further, FIG. 6 (d) shows the case where the vehicle advances and the road R1 branches off. The candidate road newly generated by the branch is represented by using the same symbol “R3” as the road deleted in the state of FIG. By the processing of step 104, the contents of the storage area 26a become as shown in FIG. The branch history data is also as shown in FIG.

The candidate road R1 and the candidate road R3 do not have a difference in overall accuracy of more than 15, and neither of them has a difference of 31 from the lowest overall accuracy of all the candidate roads R0 to R3. It is assumed that the process progresses and becomes as shown in FIG. In the state of FIG. 7E, the candidate road R1 is further branched, and the storage area of the candidate road R4 is set in the storage area 26a by the processing of step 104 as shown in FIG. 9E. Also, the branch history data is as shown in FIG. 10 (c) by writing "1" in the fourth digit of the content of FIG. 10 (b).

In the processing of step 260, the candidate road R
Since 1, R3 and R4 form one branch group, the difference from the lowest overall accuracy of these three candidate roads R1, R3 and R4 is calculated. For example, if the candidate road R1 has the lowest overall accuracy, the overall accuracy of the candidate road R1 is subtracted from the overall accuracy of the candidate road R3. If the value is 15 or less, the candidate road R3 is not deleted. Candidate road R4
The same applies to.

It is assumed that the candidate roads R3 and R4 have not been deleted and the vehicle has proceeded to the state shown in FIG. 7 (f). In this state, the candidate road R0 is already two candidate roads R5.
R7 is branched. Further, the candidate road R2 branches one candidate road R6. Therefore, the contents of the storage area 26a at this time are as shown in FIG. 9 (f). The branch history data is also as shown in FIG. The branch history data is written in a 16-bit memory for each branched group. Therefore, in the deletion processing of step 260, first, for candidate roads R1, R3, R4 that are the branch groups of candidate road R1, then for candidate roads R0, R5, R7 that are the branch groups of candidate road R0, and then for the candidate roads. Candidate road R that is a branch group of R2
For 2 and R6, it is determined whether the condition of the above formula 2 or formula 3 is satisfied.

As a result, when the candidate road R3 is deleted from the branch group of the candidate road R1 and the candidate road R7 is deleted from the branch group of the candidate road R0, the storage area 26a
Is as shown in FIG. 9 (g). The branch history data is also as shown in FIG.

Thereafter, in the same control cycle, step 300
Although the deletion processing is performed for all candidate roads of No. 3, the data of R3 and R7 has already been deleted, so the processing load is lightened. Further, in the process of step 300, when the candidate roads R2, R5, and R6 are deleted as corresponding to the deletion target as shown in FIG.
The contents of a are as shown in FIG. 9 (h). The branch history data is also as shown in FIG. In the branch history data, all the candidate roads for the branch group of the candidate road R2 have disappeared, and the only branch group of the candidate road R0 is R0. Therefore, the two branch history data are deleted and only the branch group of the candidate road R1. Becomes

Further, when the vehicle further progresses from the state of FIG. 8 (g) and the candidate road R0 is out of the error range of the vehicle position indicated by the chain line, the candidate of the state of FIG. 9 (h) is selected. The area of the road R0 will be deleted. In the present embodiment, in step 200, inappropriate road candidates are excluded by relative comparison for each group of candidate roads having a branching relationship. Here, the relative comparison is to compare the difference in relative overall accuracy between the candidate roads in the group. For this reason, candidate roads are retained as they have a relatively low overall accuracy, and as candidate roads are deleted as they become higher. In this way, only inappropriate candidate roads are excluded, not necessarily one. Further, if there are two or more candidate roads after branching, the branch relationship is stored and held as shown in FIG. 10, so there is no need to narrow down to one at a time immediately after branching, and each branch is performed in step 200. While repeating the check for each group, the candidate roads having a difference in the total accuracy may be sequentially deleted. That is, after referring to the branch relations stored as shown in FIG. 10, the possibility that the road is an inappropriate road in each branch relation is sufficiently increased, that is, the relation of Expression 2 or Expression 3 is satisfied. Only then can the relevant road be eliminated. Therefore, as in the conventional case, it is possible to reduce the possibility of erroneous estimation due to always narrowing down to one at a time immediately after branching.

Further, if there is an inappropriate thing as a whole, in steps 300 and 400, the result of comparison between the traveling locus and the road pattern, the estimated position / direction of the vehicle, and the road position / direction are estimated. Since the roads are deleted based on the comparison result of 1, even if the candidate road branches, regardless of that, it is possible to simply delete the inappropriate road from the candidate roads as a candidate. Therefore, even if the candidate roads left by the deletion in step 200 are truly inappropriate, they are always excluded.

Therefore, it is possible to prevent erroneous estimation as much as possible, and it is possible to prevent the memory shortage by appropriately removing from the candidate roads in the deletion processing of steps 200, 300 and 400, and to prevent the burden of pattern matching from increasing. . Further, the exclusion criterion in step 200 is easier than that in step 300. this is,
This is because in the branch group, even if the difference between the candidate roads that are not in a branching relationship is relatively small, the inadequacy is clearly shown. Inappropriate candidate roads can be deleted, and the memory shortage and pattern matching load can be prevented earlier. Furthermore, the load of the deletion process in step 300 following step 200 is reduced. In particular, since all candidate roads are sorted in step 300, reducing the candidate roads as much as possible is effective in reducing the burden.

As described above, it is possible to prevent the correct road from being deleted, and the candidate roads that have branched are appropriately deleted. Therefore, it is possible to prevent erroneous estimation as much as possible, and prevent a memory shortage and an increase in pattern matching load. it can. In the present embodiment, the vehicle speed sensor 1, the azimuth sensor 2, and the electronic control circuit 20 correspond to the traveling locus detecting means and the vehicle position / direction estimating means, and the traveling is input from the vehicle speed sensor 1 performed by the electronic control circuit 20. The process of calculating the current locus of the vehicle by calculating the current position at a predetermined timing based on the traveling distance obtained by integrating the speed and the traveling direction obtained from the azimuth sensor 2 and accumulating the current position by a predetermined number, This corresponds to the processing as the traveling locus detection means. Among them, the process of integrating the traveling speed input from the vehicle speed sensor 1 to obtain the traveling distance and the process of calculating the current position at a predetermined timing based on the traveling direction and the traveling distance obtained from the azimuth sensor 2 are the vehicle. Corresponds to the processing as the position / direction estimation means of. The map memory 4 corresponds to map information storage means.

The electronic control circuit 20 corresponds to the estimating means, the candidate road deleting means, the branch relation storing means, and the in-branch deleting means, and the electronic control circuit 20 carries out step 1
04 and 109 correspond to the processing as the estimating means, step 300 corresponds to the processing as the candidate road deleting means of claim 1, and the branch history data creation processing performed in step 104 is the processing as the branch relation storing means. And step 200 corresponds to the process as the in-branch deleting means.
Further, steps 300 and 400 correspond to the processing as the candidate road deleting means of claim 2.

[Brief description of drawings]

FIG. 1 is a block diagram of a vehicle traveling position display device according to an embodiment of the present invention.

FIG. 2 is a flowchart of road estimation processing performed by an electronic control circuit 20.

FIG. 3 is a flowchart of a deletion process in the process.

FIG. 4 is a flowchart of a branch group deletion process within the branch group.

FIG. 5 is an explanatory diagram showing appearance states of candidate roads.

FIG. 6 is an explanatory diagram showing appearance states of candidate roads.

FIG. 7 is an explanatory diagram showing appearance states of candidate roads.

FIG. 8 is an explanatory diagram showing appearance states of candidate roads.

FIG. 9 is an explanatory diagram showing stored contents of a candidate road.

FIG. 10 is an explanatory diagram showing stored contents of a branch history.

FIG. 11 is an exemplary diagram showing a basic configuration of the invention of claim 1;

FIG. 12 is an exemplary diagram showing a basic configuration of the invention of claim 2;

[Explanation of symbols]

1 ... Vehicle speed sensor 2 ... Direction sensor 4 ... Map memory 6 ... Control switch 20 ... Electronic control circuit 22 ... CPU 24 ... ROM 26 ... RAM 26a ... Candidate road storage area 26b ... Branch history storage area 28 ... Input / output circuit 30 … Common bus 32… CR
T controller 34 ... CRT

Claims (5)

[Claims] 1. A vehicle running locus detecting means, a map information storing means, and a candidate road extracted from roads near the vehicle stored in the map information storing means, a road pattern of the candidate road and the running locus. Estimating means for comparing the traveling locus detected by the detecting means to estimate a traveling path, and an inappropriate road as a candidate is deleted from the candidate roads based on the comparison result between the traveling locus and the road pattern. A vehicle traveling position estimation apparatus including: a candidate road deleting unit, and a branch relation storing unit that stores a branch relation each time the candidate road branches, and a branch relation stored by the branch relation storing unit. Based on the above, for each group of candidate roads having a branching relationship, a vehicle-in-branch deleting means for deleting roads inappropriate as candidates by relative comparison is provided. Line position estimation device. 2. A candidate road is extracted from the vehicle running locus detection means, the vehicle position and direction estimation means, the map information storage means, and the road near the vehicle stored in the map information storage means, and the candidate roads are extracted. An estimating means for estimating a traveling path by comparing a road pattern of a road with a traveling locus detected by the traveling locus detecting means, a comparison between the traveling locus and the road pattern, and the position / direction estimating means. In a vehicle traveling position estimation device including: a candidate road deleting unit that deletes an unsuitable road from the candidate roads based on a comparison between the estimated vehicle position / direction and the road position / direction, Further, each time a candidate road branches, based on the branch relation storage means for storing the branch relation and the branch relation stored by the branch relation storage means, the candidate roads having the branch relation are grouped. A vehicle traveling position estimation device comprising: a branching deletion unit that deletes an inappropriate road as a candidate by relative comparison for each group. 3. The vehicle traveling position estimating device according to claim 1, wherein the in-branch deleting unit deletes the road under a condition that is easier to delete than the deleting process executed by the candidate road deleting unit. 4. The comparison between the traveling locus and the road pattern in the candidate road deleting means finds the degree of approximation of the pattern by pattern matching between the traveling locus and the road pattern, and obtains the degree of approximation from the highest degree of approximation. Is a process of deleting roads having a degree of approximation lower than a predetermined value from the candidate roads, and the inside-branch deleting means sets the predetermined value to a smaller value, for each group of candidate roads having a branching relationship, The vehicle traveling position estimation device according to claim 3, wherein a road having an approximation degree lower than a highest approximation degree by a predetermined value or more is deleted from the candidate roads. 5. The vehicle traveling position estimating device according to claim 1, wherein the in-branch deleting unit performs the deleting process before the deleting process executed by the candidate road deleting unit.