JPH02130414A - Running path display device - Google Patents

Abstract

PURPOSE:To correct the current position of a moving object accurately and efficiently by replacing a running locus of the moving object and a road on a map with dot patterns, which are overlapped to match them at a position to give the best overlapping. CONSTITUTION:Under the control of a signal processor 3, as a moving object runs at each fixed distance L preset, a running locus P of the moving object in the distance is shown by a pattern P' having a plurality of dots at fixed interval and a specified width range. Likewise, roads R on a map are shown by a pattern R' having dots at a fixed interval and a specified width range. Then, the patterns P' and R' of the running locus and the roads given by a plurality of dots are overlapped sequentially changing relative positions thereof to determine the number of dots overlapped. The running locus P of the moving object deviated is made to match the roads R on the map at an overlapping position where the number of dots determined is at its maximum.

Description

[Detailed Description of the Invention] Lf! TECHNICAL FIELD The present invention relates to a driving route display device that displays the current position of a moving object on a road map displayed on a screen in advance while determining the current position of the moving object.

U-jutsu - Conventionally, as will be explained in detail later, when driving a car, etc. in an unfamiliar area, appropriate guidance is given so that the driver does not deviate from the planned course and get lost. Therefore, as the vehicle travels, a distance detector detects the travel distance and a direction detector detects the direction of travel, and from these detected values, the ever-changing current position of the vehicle on two-dimensional coordinates is calculated one after another. A driving route display device that allows a driver to confirm the current position by updating and displaying the current position determined by point information on a road map displayed on a screen in advance. is being developed.

However, in such a driving route display device, it is unavoidable that position errors occur due to factors such as the accuracy of each detection when detecting distance and direction according to the driving condition of the car, etc., and as the car etc. progresses, position errors occur. Therefore, as the errors accumulate, the updated and displayed current position gradually deviates from the road on the map, making it impossible to determine which road on the map the vehicle is traveling on. There is.

Therefore, by matching the road pattern on the map with the travel trajectory pattern obtained by storing and retaining the current position data that is updated sequentially as the vehicle travels, it is possible to eliminate errors on the road. It is conceivable to have the current position that has deviated be corrected. In other words, all roads are extracted from the road network in the vicinity of the current location, and the compatibility between the pattern of each road and the pattern of the travel trajectory of a car, etc. is examined to find the pattern with the highest matching rate. This road is regarded as the road on which the vehicle is currently traveling, and the display position of the current position is moved to the matched road.

However, if such a correction method is used, if the roads in the vicinity of the current location are complex, it is difficult to extract all the roads and compare each road pattern with the pattern of the travel trajectory of a car, etc. It takes a lot of time to perform matching processing.

1. The present invention has been made in consideration of the above points, and it corrects the current position of a moving object that has deviated from the road due to an error by matching the pattern of the traveling trajectory of the moving object and the road on the map. An object of the present invention is to provide a driving route display device that can perform the matching process efficiently and optimally when performing the matching process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of the configuration of a travel route display device according to the present invention, which includes a distance sensor l that outputs a pulse signal for each unit travel distance according to the rotation of a car tire, and a A rate-type direction sensor 2 detects angular velocity and outputs a signal proportional to the amount of change in direction as the vehicle travels, and a distance sensor 1 counts the number of pulse signals to measure the travel distance of the vehicle. By calculating the direction of travel according to the output signal of the sensor 2, the X-
A signal processing device consisting of a microcomputer that calculates the position on the Y coordinate through sequential calculations and controls the entire system! 3, and a travel trajectory memory bag that sequentially stores the data of the position on the X-Y coordinates that changes every moment obtained by the signal processing device 3, and holds it as finite continuous position information corresponding to the current position of the car. [(RAM)4
, a map information storage medium 5 in which a plurality of map information is stored in advance in file units, and a storage medium playback device 6 that selectively reads necessary road map files from the storage medium 5.
The map surface image is displayed on the screen according to the read map file, and the current position of the car is displayed based on the position data stored in the travel trajectory memory bag [4]. A display device 7 that constantly updates and displays the travel trajectory and current direction of travel on the same screen as the vehicle travels, and a signal processing device? 13, and the display bag r! 17 to select and specify the map to be displayed, set the starting point of the vehicle on the displayed map, give commands to display the driving trajectory, etc., change the direction of the displayed map and the driving path, and its display position. Shift, map and partially enlarged display of the driving trajectory.

An operating device f! that allows you to change display format settings, such as selecting a display scale, as appropriate. ! 8.

With this configuration, one selectively read map is displayed on the screen of the display device 7, and the signal processing device 3 presets the map according to the vehicle traveling from the starting point set on the map. The current position on the X-Y coordinates is calculated moment by moment according to the scale factor of the map, and the calculation results are stored in the travel trajectory storage device i! 4 and the stored contents are updated, and the stored contents are constantly read out and sent to the display device 7. As a result, the display device 7 displays, for example.

As shown in Fig. 2, on the map displayed on the screen are a display mark Ml indicating the current position of the vehicle, a display mark M2 indicating the direction of travel of the vehicle at the current position, and a display mark M2 indicating the direction in which the vehicle is traveling from the starting point S to the current position. Travel trajectory display mark M
3 is displayed in a simulated manner following the driving state of the car.

The above configuration and operation are the same as the conventional travel route display device described at the beginning.

Therefore, in such a driving route display device.

As shown in Figure 3, due to the cumulative error mentioned above, the current position and the travel trajectory up to that point gradually deviate from the road on the map as the vehicle travels, and eventually It becomes impossible to judge whether the vehicle is driving at a certain point.

In one of the travel route display devices of the present invention, under the control of the signal processing device 13, as shown in FIG.
Each time the moving object travels (approximately 2 km), the traveling trajectory P of the moving object during that time is formed into a pattern P' of a plurality of dots at fixed intervals (e.g., 10 m intervals) and with a predetermined width (e.g., 20 to 30 m width). In addition, as shown in Figure 4 (b), each road R on the map is
Similarly, a pattern R' of a plurality of dots is formed at regular intervals and with a predetermined width.

The patterns P' and R' between the travel trajectory and the road represented by the plurality of dots are successively superimposed while changing their relative positions, and the number of dots that overlap with each other is calculated, and the number of dots that are overlapped with each other is determined. At the superimposed position, the traveling trajectory P of the moving object that has become misaligned and the road R on the map
It is characterized by the fact that it is matched with the following.

For example, one specific algorithm for this processing is executed as follows.

(D First, at the current display position of the traveling trajectory when the moving object has traveled a certain distance, AND processing is performed on the dot pattern P' of the traveling trajectory P and the dot pattern R' of the road R, and the overlapping dots are Count the numbers.

■Next, at the current display position, dot pattern P
' is rotated clockwise by θ=1°, AND processing is performed on the dot pattern P' of the traveling trajectory P and the dot pattern R' of the road R, and the number of overlapping dots is counted.

■Furthermore, with the dot pattern P' rotated counterclockwise by O=1'' at the current display position, AND processing is performed between the dot pattern P' of the travel trajectory P and the dot pattern R' of the road R. and count the number of overlapping dots.

■Next, move the current display position of the travel trajectory P up and down.

The above-mentioned processes (1) to (2) are performed with the image being shifted by one dot in each direction: left, right, diagonally upper right, diagonally lower right, diagonally upper left, and diagonally lower left.

(D) Then, in the above 27 ways of overlapping, the overlapping position where the number of dots is the largest is found.

([F] Next, at the overlapping position where the number of dots is the maximum, perform the AND process again using the 27 ways of overlapping described above, count the number of overlapping dots, and calculate the previous maximum number of dots. Find an overlapping position with a maximum number of dots greater than .

(2) The above process is repeated until no superposition position with a larger maximum number of dots than the previous one is found.

■If the maximum number of dots finally obtained exceeds the threshold set in advance as a matching tolerance, then the traveling trajectory P and the road R can be matched at that overlapping position. shall be

(2) At that time, if the maximum number of dots finally obtained is less than the threshold value, the following hierarchical processing is performed continuously.

In that case, in order to be able to see the overlapping state of the travel trajectory P and the road R over a wider range, the travel trajectory P and the road R may be spaced at a wider interval than before (for example, 40
After forming coarse dot patterns P", R' with spacing (m interval) and width (for example, 80 to 120 m width), while changing the relative position of each pattern P', R' in the same way as described above, (The rotation angle 0 of the running trajectory P at this time is set to, for example, 8 degrees.) The maximum value of the number of dots that overlap each other when the one-car pattern P1R' is superimposed is determined.

Then, both patterns P' when the maximum number of dots sequentially determined exceeds a threshold separately set in advance.
, R' is searched for and transferred to the overlapping position of the fine dot patterns P' and R', and the processes Φ to (2) described above are executed again from that overlapping position.

As described above, according to the present invention, the traveling trajectory P of the moving object and the road R on the map are each replaced with dot butter having a predetermined density, and while changing the relative positions of the two,
By overlapping each dot pattern like a transparent painting,
We try to match the two at the position where they overlap best.

It becomes possible to accurately and efficiently correct the current position of a moving object that has deviated from the road on the map.

In particular, the travel route display device according to the present invention displays the travel trajectory of a moving object as a pattern of a plurality of dots at regular intervals and with a predetermined width, and also displays each road on a map at regular intervals. A means for representing a pattern of a plurality of dots with an interval of A means to find the number of dots.

The method is designed to match the travel trajectory of the moving object with the road on the map at the superimposition position where the determined number of dots is maximized. Matching the pattern,
When correcting the current position of a moving object that has deviated from the road due to an error, this method has an excellent advantage in that matching processing can be performed efficiently and optimally.

...Operating device

Claims (1)

[Claims] While detecting the traveling distance and direction of the moving object, the current position on the two-dimensional coordinates, which changes every moment as the moving object moves, is calculated sequentially, and the data of the calculated current position is stored and moved. In a driving route display device that updates and displays the current position of a moving object on a screen on which map data is read out in advance from a storage medium and a predetermined road map is displayed, while determining the traveling trajectory of the moving object.
The trajectory of a moving object is represented by a pattern of multiple dots at regular intervals and with a predetermined width, and each road on the map is represented by a pattern of multiple dots at regular intervals and with a predetermined width. means for superimposing each pattern of a travel trajectory and a road, each represented by a plurality of dots, while changing the relative position, and determining the number of dots that overlap each other; A driving route display device characterized in that it takes means for matching a driving trajectory with a road on a map at a superimposed position.