JPH06194183A - Present position display device for moving body - Google Patents

Abstract

PURPOSE:To improve the correction precision of the distance error in a long- distance linear travel. CONSTITUTION:A corner detection failure is judged by 45 basing on the corners and corresponding nodes detected by 44 in a travel locus storing estimated positions as the travel locus by 43. The distance error is calculated by 46 in consideration of the judged result and the width of the road, and the inter-corner information between true corners among corners detected in the travel locus is extracted by 47. A prescribed number of error data are retrieved and obtained by 49 from 48 basing on the error data accumulated in 48 and the present travel information formed by 47 in a linear travel after the inter-corner information becomes a fixed quantity. The average value of the prescribed number of error data retrieved and obtained is obtained by 50 as the correction value for the accumulated error in the linear travel, and the displayed present position is corrected by 51 basing on the correction value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current position display device for a mobile unit which is mounted on the mobile unit and estimates and displays the current position of the mobile unit, and more particularly to a display position correction method.

[0002]

2. Description of the Related Art As is well known, a current position display device for a moving body is being developed and put into practical use in order to support the operation of a moving body such as an automobile. Map data including road data obtained by digitization is stored in advance, and while recognizing the current location of the mobile body, the map data of a certain area including the current location is read from the storage device, and the current location of the mobile body is read. A map of the surrounding area is displayed on the screen of the image display device, and in order to display the current position of the moving body on the displayed map, the moving distance of the moving body is measured by the distance sensor, and the traveling direction of the moving body is measured by the direction sensor. The present position of the moving body is estimated based on the obtained value, and the estimated position is corrected to the position on the road of the map by collating with the map data read from the storage device.

The operation of correcting the estimated position to the position on the road of the map is called map matching, but since the output data of the distance sensor has an error, the correct current position cannot be estimated as it is, Therefore, the current position of the moving body displayed on the screen of the image display device also has an error. In particular, long-distance straight running causes a problem because errors are accumulated.

Therefore, in general, for example, turn left and enter
Detects two adjacent inflection points or crossings,
The distance error is accumulated based on the distance between them, and the correction value calculated from the accumulated data is reflected in the subsequent current position display. Specifically, for example, Japanese Patent Laid-Open No. 3-27083 (in-vehicle navigation device)
As shown in, a separate program (FIG. 2 of the publication) for correcting the output data of the distance sensor by detecting the intersection is separately prepared, and the correction program is executed by key input.
Based on the obtained corrected output data, the map around the current position of the moving body displayed on the screen of the image display device and the current position of the moving body are defined.

[0005]

By the way, the main purpose of the correction of the distance error is to cancel the accumulated error during long-distance straight running, but it is necessary to obtain accurate distance error data as a premise. In addition to the error of the distance sensor, the road width (width) influences the distance error. Furthermore, when the vehicle does not smoothly turn at an intersection or meanders due to some obstacle, it may not be possible to determine which of the plurality of corners in the running trajectory is the true corner, and corner detection may fail. . Although the influence of the width and the failure of the corner detection have a great influence on the accuracy of the acquired distance error data, the accuracy of the distance error data is poor because the conventional method does not take such consideration into consideration.

Further, since this distance error is easily influenced by the traveling state at that time, ideally the correction amount is calculated using past distance error data having a traveling state similar to the present traveling state. However, it is also necessary to consider distance errors due to digitization of roads. This means that if the error of the distance sensor is assumed to be a small constant value,
This is self-evident because the distance error is large in areas with severe ups and downs, and on the other hand, the distance error in the plain is relatively small. Therefore, when using the past distance error data, the error data of the surrounding area of the present location should be referred to.

However, in the conventional method, such consideration is not taken, and since the output data of the distance sensor is corrected by simply using the average of all the past distance error data, an appropriate correction amount can be obtained. There is also a problem that calculation is difficult and it is difficult to improve matching performance and correct accuracy of accumulated error in long-distance straight line traveling.

The present invention has been made in view of such a conventional problem, and an object thereof is to make it possible to accurately obtain distance error data which is basic data for correction and to obtain some past distance error data. It is an object of the present invention to provide a current position display device for a moving body, which allows appropriate error data to be selected from among the above, thereby improving the accuracy of correction of the accumulated error during long-distance straight travel.

[0009]

In order to achieve the above-mentioned object, the present position display device for a moving body of the present invention has the following constitution. That is, the present position display device for a moving body of the present invention is a device mounted on the moving body; means for detecting the moving distance and moving direction of the moving body; means for storing map data; A signal processing unit that outputs the current position of the moving body, the current position calculated from the corner, and the corrected current position based on the traveled distance and the traveled direction and the map data; and displays the current position on the displayed map. In addition, when the corner is detected during the display, the current position calculated from the corner is preferentially displayed, and the corrected current position is displayed again. An image display device; And a processing unit for estimating the current position of the moving body based on the detected moving distance and moving direction; Basic matching means for obtaining a correction value for correcting the final estimated position of the measured position to a position on one road retrieved from the map data storage means, and outputting the correction value as the current position; A means for storing as a; a road link having a shape that matches the shape of the travel locus is searched from the map data storage means when the corner is detected in the stored travel locus, and the travel is performed in the searched road link. A corner that detects a node (hereinafter, "corresponding node") corresponding to a corner detected on the trajectory, outputs the position of the corresponding node to the image display device as a correction position of the corner, and outputs the corner and the corresponding node. Matching means; read from the map data storage means as a matching link for the stored traveling locus. When a refraction point or an intersection is detected in a road link which is assumed to travel the emitted mobile body, it is determined whether or not the node indicating the detected refraction point or the intersection and the corresponding node input from the corner matching means. A corner detection failure determining means; a distance error between each corner except the corner which the corner matching failure determination means determines to be inconsistent in response to the corner output from the corner matching means and the corresponding node, is read from the map data storage means. Means for calculating with consideration of width information; between corners output by the corner matching means and corresponding corners, except for corners determined by the corner detection failure determination means as mismatches in the stored traveling loci Position coordinates of start and end corners and Extracting and outputting inter-corner information including the moving distance, the average speed, and the average acceleration of the moving body between the corners, and performing a straight-line traveling of a certain value or more from the most recent corner in the stored traveling locus. It is possible to detect that, and when the accumulated amount of the formed and output inter-corner information is equal to or more than a predetermined value, the current traveling information (position coordinates, from the latest corner to the current position).
Additional information extracting means for extracting and outputting (moving distance, average speed, average acceleration); inter-corner data storage means for accumulating the distance error data and the inter-corner information; the corner based on the current traveling information Means for retrieving distance error data between corners from the inter-data storage means; means for calculating an average value of the retrieved distance error data between corners as a correction amount;
Means for correcting the current position output by the basic matching means based on the calculated correction amount;

[0010]

Next, the operation of the present position display device for a moving body of the present invention constructed as described above will be explained. As described above, the distance error between the corners includes the influence of the road width and the failure of the corner detection in addition to the error of the distance sensor. Therefore, it is not sufficient to simply correct the output data of the distance sensor. Further, the distance error depends on the running state at that time and the ups and downs of the road which cannot be predicted by the map data.

Therefore, in the present invention, the current position calculation means estimates the current position based on the moving distance and the moving direction of the moving body, and the basic matching means compares the estimated position with the map data to determine the current position of the moving body. At this time, the estimated position is stored in the form of a running locus, and at the same time, based on the corners and corresponding nodes detected by the corner matching means in the stored running locus, the corner detection failure determination and this corner detection failure Distance error calculation considering the judgment result and the road width is performed in parallel, and the inter-corner information is extracted between the true corners of the corners detected in the traveling locus, and the distance error data obtained And the information between the corners is accumulated, and a predetermined number of distance data between the corners is based on the current running information formed during straight running after it has reached a certain amount. Search acquired, it corrects the cumulative error at the time of straight running by the average value of the corner distance error data of a predetermined number that the search acquired are so as to modify the displayed current position.

In other words, since the error data obtained in the present invention considers the width of the road, it is possible to absorb the error associated with the digitization of the map to some extent, and the failure in corner detection is also taken into consideration. Distance error data can be acquired. Furthermore, from the accumulated distance error data, some data at the current position are searched using the position coordinates between corners and the traveling distance, speed, and acceleration between the corners as parameters, and the distance error data that have been examined are not used. . Therefore, the correction amount for the accumulated error during long-distance straight running is calculated more appropriately and the map matching performance is improved, so that the accuracy of the display position is further improved as compared with the conventional case.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 illustrates a current position display device for a moving body according to an exemplary embodiment of the present invention. The present position display device is mounted not only on the vehicle but also on a moving body (for example, a bicycle) that moves on the road. Basically, the distance sensor 1, the direction sensor 2, and the map data storage device 3 are provided. The signal processing unit 4 and the image display device 5 are included. The map data storage device 3 also stores road width information, and the screen of the image display device 5 is designed so that a map around the current location of the moving body is read from the map data storage device 3 and displayed. Has become.

The signal processing unit 4 is composed of a so-called computer system, the main functional blocks of which are the current position calculating means 41, the basic matching means 42,
Travel locus storage means 43, corner matching means 44,
Corner detection failure determination means 45, distance error calculation means 4
6, additional information extraction means 47, inter-corner data storage means 48, data search means 49, correction amount calculation means 50, and current position correction means 51, and a display control means of the image display device 5 is included although not shown. . Hereinafter, for convenience of description, the moving body will be described as a vehicle.

In FIG. 1, a distance sensor 1 and a heading sensor 2 detect the running distance and the heading of the vehicle and output them to the present position calculating means 41, respectively. Current position calculation means 4
1 captures each output data of the distance sensor 1 and the azimuth sensor 2 at regular intervals, and estimates the current position of the vehicle at each capture time point based on the following mathematical formula 1. In Equation 1, P _n-1 (x _n-1 , y _n-1 ) is the previous estimated position, and P _n (x
_n , y _n ) is the current estimated position, L is the traveling distance, and θ _CAR is the traveling azimuth (relative azimuth) of the vehicle. The estimated position at each time is the basic matching means 42 and the traveling locus storage means 4.
3 is output.

[0016]

## EQU1 ## x _n = x _n-1 + L cos θ _CAR y _n = y _n-1 + L sin θ _CAR

The basic matching means 42 has a predetermined number of estimated positions P _i (i
= 1, 2, ..., N) to obtain a correction value for correcting the final estimated position P _n to a position on one road retrieved from the map data storage device 3, and outputs it to the image display device 5 as the current position. .

For example, as shown in FIG. 2, if P _r is the previous correction position, P ₁ , P ₂ , ..., P from this correction position P _r as the starting point within the subsequent fixed traveling distance period. _n
Since each estimated position of P is input in this order, a distance P _{r + 1} equal to the distance from the corrected position P _r to the final estimated position P _n is obtained on the road when the final estimated position P _n is input. This is the corrected position this time.

The running locus storage means 43 updates and stores, for example, a past fixed amount of estimated position P _a (a = 1, 2, ..., M; where m> n) as a running locus, and always keeps the fixed amount of the fixed amount. Manage guess position. Specifically, since the distance from the corrected position P _r to the final estimated position P _n is the interval at which the basic matching means 42 is activated, a plurality of P _{r to} P _n are managed as one set. That is, if P _{r to} P _n are called control vectors, the corner matching means 44
And corner detection failure determination means 45 and additional information extraction means 4
7 means that a predetermined number is read out using this management vector as a unit and is used as a traveling locus.

The corner matching means 44 investigates whether a corner exists in the input running locus, and when the corner is detected, the map data storage device 3 retrieves a road link having a shape matching the shape of the running locus. Then, in the searched road link, the node (hereinafter, “corresponding node”) corresponding to the corner detected in the traveling locus is detected, and the position of the corresponding node is set as the correction position of the corner, and the current position is re-established. The corresponding node is output to the image display device 5 and the corresponding node is detected as the corner detection failure determination means 4.
5) Distance error calculation means 46 for the corner and the corresponding node
To the additional information extraction means 47, respectively.

A node is a node in the digitized road data that includes an inflection point or an intersection on the road, and the entire node connecting the nodes is called a road link.
And the inflection point in the actual running trajectory is called a corner,
It is designed to be distinguished from those on road links.

Next, the corner detection failure determination means 45, the distance error calculation means 46, and the additional information extraction means 47 respond to the corner detection by the corner matching means 44 simultaneously and in parallel, and determine the corner detection failure. The required error data is calculated and the required additional information (inter-corner information and current running information) is extracted, and the calculated error data and the extracted inter-corner information are stored in the inter-corner data storage means 48. In addition, the extracted current travel information is given to the data search means 49, and the correction amount calculation means 50 obtains the correction amount for correcting the accumulated error during long-distance straight line travel based on the retrieved distance error data. The operation is performed as shown in FIG.
Hereinafter, description will be given with reference to FIG.

In FIG. 3, the corner matching means 4
When corner 4 detects a corner (step 1), corner detection failure determination means 45 that has received the "corresponding node" performs a corner detection failure determination operation (step 2), and determines whether or not detection has failed (step 3). ). When the determination result is affirmative (YES), it notifies the distance error calculation means 46 and the additional information extraction means 47 that the detection has failed, that is, the corner detected by the corner matching means 44 is not a true corner. Distance error calculating means 46 and additional information extracting means 4
At 7, each failure flag managed by itself is turned on (step 4). In addition, the determination result of step 3 is negative (N
In the case of O), it is determined that the detection is successful and the fact is transmitted to the additional information extracting means 47 (step 5).

The operation of step 2 is performed as follows. That is, the corner detection failure determination means 45 is provided with a determination flag and a counter in order to determine whether the corner detected by the corner matching means 44 is true or false, and the matching link for the traveling locus stored in the traveling locus storage means 43 (that is, the link). The road link that the vehicle is supposed to travel) is read from the map data storage device 3, and the heading difference is successively monitored at the matching link. When the current heading includes a heading difference of a certain value or more from the previous heading, a refraction point Alternatively, it is determined that there is a node indicating an intersection, the determination flag is turned ON, and the counter is activated at the same time (FIG. 4A).

This counter counts the distance on the matching link where it can be determined that the traveling locus has completely passed through the node after the detection of the node indicating the inflection point or the intersection on the matching link. Specifically, since the lengths of the management vectors (P _{r to} P _n ) described above indicate a constant traveling distance such as 20 m, a predetermined number of the management vectors, for example, a predetermined number of 5 or more, are provided. To count.

The counter is a management vector (P _{r to} P _n )
When a predetermined number of items are counted, they are reset, and at the same time, the determination flag is turned off.

When a node indicating a refraction point or an intersection is detected, it is determined whether or not the detected node and the corresponding node input from the corner matching means 44 coincide. Before the counter is reset, that is, when it is determined to be "match" within the period when the determination flag is ON, the determination flag is turned off (FIG. 4 (b)). As a result, the determination in step 3 of "whether or not the detection has failed" is negative (N
O), that is, the detection is successful and the fact is transmitted to the additional information extracting means 47 (step 5).

On the contrary, if the "match" cannot be judged before the judgment flag is turned off (FIG. 4 (c)), it is judged that the corner detected by the corner matching means 44 is not a true corner. That is, the determination in step 3 of "whether detection has failed" is affirmative (YES), and the fact is transmitted to the distance error calculating means 46 and the additional information extracting means 47 (step 4).

In the distance error calculating means 46, a failure flag and two detection flags (N _S detection flag and N _e detection flag)
Is managed, and in this step 4, the failure flag is turned on.
Then, the procedure returns to step 1 to prepare for the next corner detection.

Further, the additional information extracting means 47 manages a failure flag and a data flag. In this step 4, the failure flag is turned ON and the process returns to step 1 to prepare for the next corner detection.

On the other hand, when the corner matching means 44 detects a corner (step 1), the distance error calculation means 46 and the additional information extraction means 47 which have received the "corner and corresponding node" perform the same processing as described above in step 6. It is determined whether the failure flag is turned on.

The determination in step 6 is affirmative (YES).
If it is, it means that the corner detected this time is not a true corner. Therefore, in the distance error calculating means 46 and the additional information extracting means 47, the failure flag is simply turned OFF in step 7, and the process returns to step 1. Prepare for the next corner detection.

On the contrary, when the determination in step 6 is negative (NO), since a true corner has been detected, the distance error calculating means 46 and the additional information extracting means 47 respectively operate as follows. do.

First, the distance error calculating means 46 proceeds to step 8 and determines whether or not the C _S detection flag is ON. That is, it is determined whether or not the detected corner is the starting point of the distance error calculation.

If the C _S detection flag is not ON, the determination in step 8 is negative (NO) and step 9
Proceed to step 1, turn on the C _S detection flag, and return to step 1,
In preparation for the next corner detection, if the C _S detection flag is ON, the determination in step 8 becomes affirmative (YES), and each processing of step 10 (width processing) and step 11 (distance error calculation) is executed and calculated. The distance error data is output to the inter-corner data storage means 48 (step 13),
Return to step 1 and prepare for the next corner detection.

In the distance error calculating means 46, basically, the input corner and the corresponding node are sequentially temporarily stored, and the distance error is obtained as follows.

That is, in calculating the distance error, the corner and the corresponding node which are determined not to be true corners are deleted or ignored (step 6 → route 7), but FIG.
As shown in, C _S is the previously detected corner (the corner that is the starting point of the distance calculation), N _S is the node corresponding to C _S , C _e is the corner detected this time, and N _e is C If it is a node corresponding to _e , the corresponding node N _S
The distance error rate L ε can be obtained by the mathematical formula 2 when the link distance from the same to N _e is L _link and the traveling distance from the corner C _S to the same C _e is L _DR .

[0038]

[Equation 2] Lε = (L _DR −L _link ) / L _DR

However, an actual road has a road width, that is, a width, and the vehicle normally travels in the center of the traveling lane for one lane. However, in the digitization of the road, the center of the width is adopted. When entering a road by turning right or left and then turning right or left to another road, the influence of the width appears. This is not the error of the distance sensor but the error associated with the digitization of the road, but it has not been considered in the past. Therefore, in the present invention, the influence of the width is added to the distance error calculation (width processing in step 10) to obtain a more accurate distance error (distance error calculation in step 11).

It can be understood from the above description that the influence of the width is different depending on whether the vehicle makes a left turn entry / left turn advance or a left turn entry / right turn advance. First, the determination of right turn / left turn is shown in FIG. As described above, it is performed based on the traveling locus of the vehicle when the corner is detected. That is, in FIG. 6, if the detected corner is C, the trailing end of the traveling locus entering this corner C is A, and the leading end of the traveling locus passing through this corner C is B, the vector AC is used as a reference. , Vector CB
Is pointing in the clockwise direction, it is determined to be a right turn,
If the vector CB points in the counterclockwise direction, it is determined to be a left turn.

Next, with reference to FIG. 7, the process of adding the width to the distance error calculation (step 10) will be described. In FIG. 7, roads R ₁ (width W ₁ ) and R ₂ (width W ₂ ) each have one lane on each side, and both roads are connected by road R. These roads are digitalized road links. Are formed on the center line of these roads, and the nodes on the road R ₁ (circle)
The distance of the road link connecting the road and the node (marked with a _circle ) on the road R ₂ and passing through the road R is the link distance L _{linK shown} in FIG.

On the roads R ₁ and R ₂ , the vehicle travels in the center of the driving lane. (1) When turning left from the road R ₁ to enter the road R and proceeding leftward from the road R to the road R ₂ , 2) When turning left from road R ₁ into road R and making a right turn from road R to road R ₂ , (3) turning right from road R ₁ into road R and making a left turn from road R to road R ₂ (4) Turn right from road R ₁ into road R, then from road R to road R ₂
When making a right turn to, the corner detected in each case is at the position indicated by a double circle, and the distance between these two corners is the travel distance L _DR shown in FIG.

Here, the traveling distance in consideration of the width is L _DR ′
Then, L _DR ′ in the above cases (1) to (4) can be expressed as shown in Equation 3.

[0044]

[Equation 3] In the case of (1) (left turn → left turn): L _DR ′ = L _DR +
_{(W 1/4) + (} W 2/4) For (2) (left → right _{turn): L DR '= L DR} + (W 1 /
4) In the case of (1) (turn right → turn left): L _DR ′ = L _DR + (W ₂ /
4) In the case of (2) (right turn → right turn): L _DR ′ = L _DR

[0045] In step 11, it is performed a distance error calculated by substituting L _DR 'obtained by the width processing described above L _DR of the formula 2. Since this distance error calculation is performed between two corners, the N _S detection flag is
It is reset at an appropriate time point within the period from the start of the width processing to the end of the distance error calculation so that the next distance error calculation can be performed.

Next, the additional information extracting means 47 proceeds to step 12 and extracts the corner information which is one of the additional information. This inter-corner information is used as the traveling locus storage means 43.
The position coordinates of the start-point corner and the end-point corner between the corners except for the corners determined by the corner detection failure determination means 45 in the traveling locus extracted from the above, and the moving distance, average speed, and average acceleration of the moving body between the corners. Is the content.

FIG. 8 shows an example of the extracting operation. Figure 8
In, in the middle of the figure, as shown in the "running drawing" in the middle of the figure, the section from the left corner ◎ to the right corner ◎ is divided at a predetermined timing. The travel distance is obtained as the sum of the distances between the respective timings from the number of management vectors. The speed between each timing is calculated from the traveling distance and timing time interval there, and the average of them is used as the average speed between the corners (upper part in the figure). The average acceleration between corners is obtained by quasi-accelerating the acceleration from the speed change between each timing and averaging the values (lower part of the figure). The position coordinates of the start point corner and the end point corner between each corner are obtained from the corresponding nodes supplied from the corner matching means 44.

The additional information extracting means 47 outputs the one set of the inter-corner information extracted in step 12 as described above to the inter-corner data storing means 48 (step 13), and the output timing is the distance error. This is performed in synchronization with the timing at which the calculation means 46 outputs the distance error data. That is, the distance error data between certain corners and the inter-corner information are associated and stored as a table.

The additional information extracting means 47 has a counter for managing the number of times the inter-corner information is output, and the counter is set to 1 when outputting to the inter-corner data storage means 48.
Then, it is determined whether the count value has reached a predetermined value by stepping forward (step 14).

When the count value does not indicate the accumulation of a sufficient amount of data, the determination result of step 14 is negative (NO), and the process returns to step 1 to prepare for the next corner detection.
When it is a count value that indicates the accumulation of a sufficient amount of data,
The determination result in step 14 is affirmative (YES), the data flag is turned on in step 15, and the process returns to step 1. The content of this data flag is transmitted to the data search means 49.

Regarding the operation of this data flag, the inter-corner data storage means 48 monitors the data storage amount, and the additional information extraction means 47 operates the data flag in accordance with the notification from the inter-corner data storage means 48. May be.

Next, the additional information extracting means 47 detects a corner in the running locus stored in the running locus storing means 43 and monitors the straight running distance between the corners.
When the corner detection failure determination means 45 informs that the detected corner is a true corner, it is detected in step 5 that the vehicle has run a straight line longer than a predetermined value from the true corner (most recent corner). It is determined whether it was possible.

If the determination in step 5 is negative (NO), the process returns to step 1 to move to the next monitoring operation, but if the determination in step 5 is positive (YES), the process proceeds to step 16 to see if the data flag is ON. Determine whether or not.

Then, the determination in step 16 is negative (N
In the case of O), the process returns to step 1 and moves to the next monitoring operation. However, if the determination in step 16 is affirmative (YES), the process proceeds to step 17, where the true corner (most recent corner) to the current position is detected. The current traveling information (positional coordinate, moving distance, average speed, average acceleration) is extracted by the procedure described above and output to the data search means 49 (step 1
8).

In step 18, the data retrieving means 49 retrieves the distance error data between the corners from the table of the inter-corner data storing means 48 by using the inputted current traveling information as a clue. This search operation is performed as follows: (1) distance error data between corners existing within a certain distance from the current position, (2) distance error data at a distance between corners that is about the same as the current running distance, (3) current The average speed of
This is performed by selecting distance error data based on three search criteria "distance error data at distance between corners having a value similar to acceleration" according to the procedure shown in FIG. The data can be searched and the distance error data that is different from the study is not used.

In FIG. 9, in the first stub 1, it is determined whether or not there is data corresponding to the search criterion (1) in the table (hereinafter, "error database") of the inter-corner data storage means 48. If the determination is negative (NO), the process proceeds to step 8, but if the determination is affirmative (YES), the process proceeds to step 2, and the error database is searched for data corresponding to the search criterion (1), and the searched corresponding data is searched. Is stored, and it is then determined whether or not there is data corresponding to the search criterion (2) in the stored search data (step 3).

If the determination in step 3 is affirmative (YES), the process proceeds to step 4, but the data corresponding to the search criterion (2) is selected from the search data retrieved and stored in step 2 and the selected corresponding data is selected. The data is stored, and then it is determined whether or not the selected selection data that is stored includes the data corresponding to the search criterion (3) (step 5). If the determination is affirmative (YES), the process proceeds to step 6, and conversely, if the determination is negative (NO), the process proceeds to step 8.

On the contrary, if the determination in step 3 is negative (NO), the process proceeds to step 7 and it is determined whether or not the search data retrieved and stored in step 2 includes data corresponding to the search criterion (3). If the determination is affirmative (YES), the process proceeds to step 6, and conversely, if the determination is negative (NO), the process proceeds to step 8.

In step 6, data corresponding to the search criterion (3) is selected and stored from the data selected and stored in step 4 or the data retrieved and stored in step 2.

Next, when it is determined that there is no data corresponding to the search criterion (1) in the database (step 1), the data corresponds to the search criterion (1) and also corresponds to the search criterion (2). However, when the data does not correspond to the search criterion (3) (step 5) and the data corresponds to the search criterion (1), it does not correspond to both the search criterion (2) and the search criterion (3) ( In step 7), the process proceeds to step 8 and it is determined whether or not there is data corresponding to the search criterion (2) in the error database.

If the determination in step 8 is negative (NO), the process proceeds to step 12, but if the determination is affirmative (YES), the process proceeds to step 9 to search the error database for data corresponding to the search criterion (2). Then, the searched corresponding data is stored, and then it is determined whether or not the stored search data includes data corresponding to the search criterion (3) (step 10).

Then, the determination in step 10 is affirmative (YE
In the case of S), the process proceeds to step 11, and the data corresponding to the search criterion (3) is selected from the stored search data, and the selected data is stored, but the determination in step 10 is negative (NO). If so, go to step 12.

Then, the search criteria (2) are stored in the database.
If there is no data corresponding to (step 8) and the data that meets the search criterion (2) but does not meet the search criterion (3) (step 10), proceed to step 12 and search the error database. It is determined whether or not there is data corresponding to the criterion (3).

If the determination in step 12 is affirmative (YES), the process proceeds to step 13 to search the error database for data corresponding to the search criterion (3) and store the searched corresponding data.

Then, the predetermined number of distance error data selected and stored in steps 6, 11 and 13 are output to the correction amount calculation means 50 (step 14), and the search operation is ended.
In addition, when the determination in step 12 is negative (NO), when there is no data corresponding to any of the search criteria (1) to (3), the search operation is ended as it is, but the search criteria (1) or If either of the same (2) is present, the predetermined number of distance error data selected and stored in one or both of steps 6 and 11 are output to the correction amount calculation means 50 (step 14), and the search operation is ended. .

Next, in the correction amount calculation means 50, the predetermined number of distance error data e _j (j = _j) retrieved as described above.
1, 2, ..., K) and obtains the average value as a correction factor ε ((Equation 4)). The current running distance L ₀ obtained from the additional information extracting means 47 is multiplied by the correction factor ε to obtain a correction amount. L _CAN is obtained and output to the current position correction means 51.

[0067]

[Equation 4]

Then, in the current position correction means 51, the basic matching means 42 corrects the current position output to the image display device 5 based on the correction amount calculated by the correction amount calculation means 50, and the corrected position is newly corrected. Give to 5.

As a result, in the image display device 5, the output of the basic matching means 42 is displayed in principle by the action of the above-mentioned display control means, but when the corner matching means 44 detects a corner, the current calculation is performed based on it. The position is displayed with priority, and the current position correction means 51 is also provided.
When outputs the corrected position, the corrected current position is displayed accordingly.

[0070]

As described above, according to the present position display device for a moving body of the present invention, the width of the road is taken into consideration when the error data is obtained from the traveling distance between the corners. Since it can absorb the error to some extent and also considers the corner detection failure,
More reliable distance error data can be acquired. Furthermore, from the accumulated distance error data, some data at the current position are searched using the position coordinates between corners and the traveling distance, speed, and acceleration between the corners as parameters, and the distance error data that have been examined are not used. . Therefore, the correction amount for the accumulated error during long-distance straight line traveling is calculated more appropriately and the map matching performance is improved, so that there is an effect that the accuracy of the display position is further improved as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a current position display device for a moving body according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of a basic matching unit.

FIG. 3 is a flowchart showing an operation from a corner detection failure determination means to a correction amount calculation means.

FIG. 4 is an operation explanatory diagram of a corner detection failure determination means.

FIG. 5 is a diagram illustrating the principle of distance error calculation means.

FIG. 6 is an explanatory diagram of a left turn / right turn determination method necessary for pre-processing of width processing.

FIG. 7 is an explanatory diagram of a method of calculating a traveling distance in consideration of a width.

FIG. 8 is an explanatory diagram of an operation of additional information extraction means.

FIG. 9 is a flowchart of an operation procedure of the data search means.

[Explanation of symbols]

 1 distance sensor 2 azimuth sensor 3 map data storage device 4 signal processing unit 5 image display device 41 current position calculation means 42 basic matching means 43 traveling locus storage means 44 corner matching means 45 corner detection failure determination means 46 distance error calculation means 47 addition Information extraction means 48 Inter-corner data storage means 49 Data retrieval means 50 Correction amount calculation means 51 Current position correction means

Claims (1)

[Claims] 1. A device mounted on a moving body; means for respectively detecting a moving distance and a moving direction of the moving body; means for storing map data; and detected moving distance, moving direction and the map. A signal processing unit that outputs the current position of the moving body based on the data, the current position calculated from the corner, and the corrected current position; and displaying the current position on the displayed map and displaying the current position An image display device which, when detected, preferentially displays the current position calculated from the corner and displays the corrected current position again;
The signal processing unit estimates the current position of the moving body based on the detected moving distance and moving direction; and a final estimated position of a predetermined number of the estimated positions input one by one within the period for each constant traveling distance. A basic matching unit that obtains a correction value for correcting a position on one road retrieved from the map data storage unit and outputs the correction value as the current position; a unit that stores a certain amount of the estimated position as a traveling locus;
When the corner is detected in the stored traveling locus, a road link having a shape matching the shape of the traveling locus is searched from the map data storage means, and the corner detected in the traveling locus is found in the searched road link. Corner matching means for detecting a corresponding node (hereinafter, “corresponding node”), outputting the position of the corresponding node to the image display device as a correction position of the corner, and outputting the corner and the corresponding node; When a refraction point or an intersection is detected in a road link on which the moving body is assumed to travel, which is read out from the map data storage means as a matching link for the traveled locus, a node indicating the detected refraction point or intersection and the corner matching means. Matches with the corresponding node input from Corner detection failure determination means;
The distance error between each corner except the corners which the corner matching means outputs and the corresponding nodes is determined by the corner detection failure determination means is calculated in consideration of the width information read from the map data storage means. Positions of a start point corner and an end point corner between the respective corners except for the corners which the corner detection failure determination means determines as a mismatch in the stored traveling locus upon receiving the corners output by the corner matching means and the corresponding nodes. Extracting and outputting information between corners having coordinates and moving distance of the moving body between the corners, average speed, and average acceleration, and a straight line having a certain value or more from the most recent corner in the stored traveling locus. It is possible to detect that you have run, and the information on the corners that has been formed and output. Additional information extracting means for extracting and outputting current traveling information (position coordinates, moving distance, average speed, average acceleration) from the most recent corner to the current position when the accumulated amount of information is a predetermined value or more; Inter-corner data storage means for accumulating the distance error data and the inter-corner information; means for retrieving inter-corner distance error data from the inter-corner data storage means based on the current traveling information; and the retrieved predetermined number. A means for calculating the average value of the distance error data between the corners as a correction amount; and a means for correcting the current position output by the basic matching means based on the calculated correction amount. Current position display device.