JPH0121442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a traveling position display device for a moving body such as an automobile, which displays the moving state of the moving body, such as the current position, movement trajectory, and direction of travel.

PRIOR ART In general, when driving a car at night or in unfamiliar areas, in order to provide appropriate guidance so that the driver does not deviate from the planned driving course and get lost, automatic guidance is provided on a preset road map. 2. Description of the Related Art Traveling position display devices for moving objects have been developed that display the moving status of a vehicle, such as its current location, traveling trajectory, and direction of travel.

Conventionally, in the case of this type of traveling position display device for a moving object, a distance detector detects the distance traveled by the vehicle according to the vehicle speed, and a direction detector detects the direction in which the vehicle is traveling and the amount of change thereof. Then, the current position of the vehicle, etc. on the travel route is calculated from each of these detected values, and while the results are stored and retained, continuous point information that changes every moment is displayed on the display screen on which a map of the road etc. is displayed in advance. By displaying this information, the driver can confirm the current location.

However, in such a traveling position display device for a moving object, it is unavoidable that position errors occur due to the detection accuracy of the distance detector and direction detector, and as the movement progresses, the errors accumulate and the current The location and travel trajectory up to that point deviate from the road on the map, making it difficult to determine which road the vehicle is currently traveling on.

Purpose The present invention was made in consideration of the above points, and
To provide a moving position display device for a moving body that automatically corrects the current position of the moving body displayed on a map and the travel trajectory up to that point so that it is always on the road.

Configuration An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the basic configuration of a traveling position display device for a moving object according to the present invention. Distance detector 1 that generates a signal according to the moving distance of
and a direction detector 2 that outputs a signal proportional to the direction or the amount of change in direction depending on the traveling direction of the moving body, which is composed of a rate-type gyroscope that detects the angular velocity in the yaw direction, for example, and the distance detector 2. The moving distance of the moving object is measured by counting the pulse signals from the detector 1, and the traveling direction of the moving object is determined from the output of the direction detector 2. A signal processing unit (CPU) 3 that calculates the position on the two-dimensional coordinates for each unit traveling distance and performs centralized control of the entire device, and a signal processing unit (CPU) 3 that calculates the position on the two-dimensional coordinates for each unit distance traveled, and the momentary change determined by the signal processing unit 3. A movement trajectory storage device (RAM) 4 that sequentially stores position data on two-dimensional coordinates and holds this as finite continuous position information corresponding to the current position of the moving body, and digital data in pixel units in raster mode in advance. A map information storage medium 5 in which informationized map information is stored, and a storage medium reproducing device 6 that reads necessary map information from the storage medium 5.
Then, a map image is displayed on the drawing according to the read map information, and the current position of the moving body, the previous travel trajectory, and the current location are displayed based on the position data stored in the movement trajectory storage device 4. A display device 7 that updates and displays the traveling direction etc. on the same screen every moment, gives a display command to the signal processing device 3, selects and specifies a map to be displayed on the display device 7, and changes the direction of the displayed map and travel trajectory, It consists of an operating device 8 that can shift the display position, partially enlarge the map and the travel trajectory, change display format settings such as selecting the display scale, search the map and the travel trajectory, etc. as appropriate. has been done.

With this configuration, the map accessed as appropriate is displayed on the screen of the display device 7, and as the moving object travels, the map is scaled to a preset map scale rate by the signal processing device 3. Accordingly, the current position on the X-Y coordinates (x,
y) is calculated moment by moment, and the calculation results are sequentially sent to the display device 7 and also sent to the movement trajectory storage device 4 to be stored and held, and the stored contents are constantly read out and continuously displayed to the display device 7. As shown in FIG. 2, the display device 7 displays a display mark M1 indicating the current position of the mobile object on the travel schedule map displayed on the screen, and a display mark M1 indicating the current position of the mobile object and the progress of the mobile object at the current position. A display mark M2 indicating the direction and a travel locus display mark M3 from the starting point to the current position are displayed in a simulated manner following the moving state of the moving body. At that time, as shown in Figure 3, due to cumulative errors, the current position of the moving object and its travel trajectory up to that point deviate from the road on the map, making it difficult to determine which road it is currently traveling on. It becomes difficult.

In such a traveling position display device for a moving object, the present invention is designed to combine data values of a road-related position on a map stored as digital information by the signal processing device 3 and data values of a traveling trajectory of a moving object. The deviation is judged based on a certain standard, and when the deviation becomes larger than the certain standard, the current position of the moving object displayed on the map and the travel trajectory up to that point are always changed to the road according to the road data value. I try to take measures to make automatic corrections like the one above.

At that time, for example, if the travel trajectory deviates from the road as shown in Figure 3, a search is made for a road that follows the correct travel trajectory up until then, and as shown in Figure 4, the current path is Extract road candidates A, B, and C that are likely to match the trajectory, and compare the data of each extracted road A, B, and C with the travel trajectory data that has cumulative errors. As shown in Fig. 5, the similarity is judged, and it is determined that the road B with the highest similarity is the road on which the moving object is currently traveling, and a mark indicating the current position of the moving object is placed on that road B. M1 and travel trajectory mark M
The data is corrected so that 3 is displayed. In addition, the data correction is as follows:
Specifically, this is performed by processing the entire rotation, parallel movement, enlargement, and reduction of the travel trajectory, and avoids making corrections that would change the relative positions of the point sequences of the travel trajectory itself.

Note that, as a specific means for determining the similarity, for example, the following means may be employed.

In other words, the value f _c that is obtained by integrating the difference between the change in the direction of the road R〓 and the change in the direction of the travel trajectory r〓, which are functions of distance given by the following equation, over the entire comparison interval a to b is When the travel trajectory and the road are shifted slightly back and forth, the more similar they are, the smaller the value becomes, as shown in FIG. 6, and the minimum value is obtained at a point where they almost match.

f _c (τ)=∫ ^b _a ｜R〓(τ+l)−r〓(τ)｜dl……
(1) Therefore, for each searched road A, B, C
By determining f _c and comparing each value, it becomes possible to judge similarity.

In this way, when correcting deviations in the traveling trajectory due to cumulative errors in each fixed section by performing overall rotation, parallel translation, etc. without changing the relative position of the point sequence of the traveling trajectory itself, If large errors occur in a concentrated manner, the position of the corrected travel trajectory relative to the road may become incorrect.

For example, if a slip occurs in the travel of a mobile object at point a as shown in Figure 7a, it is determined that the travel trajectory is on road D, with the deviation corrected in units of a certain section as described above. However, there is a high possibility that the vehicle is actually traveling on Road E in front of it. Furthermore, as shown in Figure b, for example, if the drive rotary rotates three or more times (the direction changes by more than 1080 degrees), the output of the direction detector at that time may contain a large error (for example, If a 1% error is included in the output of the gas rate sensor, an angular error of 10 degrees will occur in 3 rotations).
In this case as well, even if the travel trajectory is corrected so that it is on road F, there is a possibility that the vehicle is actually traveling on road G ahead.

However, especially in the present invention, it is possible to detect a large concentration of errors in the calculation of the moving position of a moving body while it is running, and to display the singular point in the running trajectory displayed on the screen at the time of detection. When correcting the deviation of the traveling trajectory due to the cumulative error mentioned above, if a singular point exists in the traveling trajectory of a certain section to be processed, the traveling trajectory is divided at that point and each The system determines the similarity between the road searched within the range of the divided travel trajectories and the travel trajectory, and corrects the deviations separately.

Furthermore, factors that can cause large errors in calculating the traveling position include slips of the moving object that result in a large rotational difference between multiple wheels (the distance detected by the distance detector is longer than the actual distance). In addition to multiple rotations of the moving object (detected by the user) and multiple rotations of the moving object, geomagnetic disturbances may occur when the moving object passes a railroad crossing, railway bridge, etc. when using a geomagnetic direction detector. Furthermore, slips of a moving object can be detected by looking at the difference in the number of rotations of each wheel, multiple rotations of a moving object can be determined by the signal processing device itself, and disturbances in the earth's magnetic field can be detected by looking at large amplitude changes in the output of the direction detector at that time. By doing so, it is possible to detect the cause.

FIG. 8 shows an example of a processing block in the traveling position display device for a moving object according to the present invention. The road data for comparison that has been retrieved is stored in the storage unit 10, and based on the stored road data, the display scale read out from the storage unit 11 that stores the original travel trajectory data before correction is adjusted. A search is executed by the road search unit 12 according to the data of the travel trajectory in the corresponding certain section. Further, the degree of similarity between the searched road and the travel trajectory is calculated in the calculation section 13, the road with the highest degree of similarity is selected in the road selection section 14, and then the travel trajectory is calculated in the correction amount calculation section 15. A correction amount is calculated so as to be on the selected road, and the correction processing unit 16 appropriately corrects rotation and parallel movement of the travel trajectory according to the correction amount, and data of the processed travel trajectory is calculated. After this is stored in the display traveling trajectory data storage section 17, the corrected traveling trajectory of the moving object is displayed on the display section 18 together with the map. In addition, the singularity detection section 25 detects, based on the detection output of the slip detection section 24 or based on the judgment of the signal processing device itself, the occurrence of a condition that intensively causes a large error in the calculation of the running position. The position of the singular point determined by the vehicle is stored in the storage unit 26, and the deviation of the travel trajectory due to the cumulative error can be corrected in appropriate divisions according to the stored data. In addition, 19 in the figure
2 is a travel distance detection unit, 20 is a direction detection unit, 21 is a current position calculation unit, 22 is a travel trajectory data storage unit, 2
3 is a display map storage section.

Effects As described above, in the traveling position display device of a moving object according to the present invention, when the traveling trajectory of the moving object displayed on the map deviates from the road, a road along the traveling trajectory is searched for. A means for extracting data on the searched roads, comparing the extracted data on each road with travel trajectory data to determine similarity, and selecting the road with the highest similarity among them. and a means for correcting the data so that the traveling trajectory is displayed on the selected road, thereby automatically correcting deviations in the traveling trajectory due to cumulative errors. In particular, a means is provided to detect a singular point that causes errors in a concentrated manner, divide the travel trajectory according to that position, and automatically correct the deviations separately for each of the points. The excellent advantage is that even if an error factor occurs that greatly disturbs the calculated travel position, it can always automatically correct deviations in the travel trajectory based on highly accurate accumulated errors without being affected by it. have.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of a traveling position display device for a moving body according to the present invention, Fig. 2 is a diagram showing an example of display contents on the display device, and Fig. 3 shows a state in which the traveling trajectory is off the road. Figures 4a, b, and c are diagrams showing the road search status, respectively.
Figures 5 a, b, and c are diagrams showing the similarity between the searched road and the travel trajectory, Figure 6 a, b, and c are diagrams showing the characteristic diagrams of the functions representing the similarity, and Figure 7. 8A and 8B are diagrams each showing the display state of a traveling locus due to a singular point, and FIG. 8 is a diagram showing an example of a processing block in the traveling position display device for a moving body according to the present invention. 1... Distance detector, 2... Direction detector, 3...
Signal processing device, 4... Movement trajectory storage device, 5...
Map information storage medium, 6...Storage medium playback device, 7
... Display device, 8 ... Operation device, 9 ... Map data storage section, 10 ... Road data storage section for verification, 1
1... Original trajectory data storage section, 12... Road search section, 13... Similarity calculation section, 14... Road selection section, 15... Correction amount calculation section, 16... Correction processing section, 17... Display trajectory data storage unit, 18...
Display section, 19... Mileage detection section, 20... Direction detection section, 21... Current position calculation section, 22... Trajectory data storage section, 23... Display map storage section, 24...
...Slip detection section, 25...Singularity detection section, 26
...Singularity memory.

Claims (1)

[Claims] 1 Based on the respective outputs of a distance detector that detects the traveling distance of the moving object and a direction detector that detects the traveling direction, the position on the two-dimensional coordinates for each unit traveling distance of the moving object is determined by a signal processing device, and Obtaining image information of the map from a digital information storage medium on which the map is recorded as digital information through a reproducing device,
In a moving position display device for a moving object that displays a map and the moving trajectory of a moving object overlappingly on the same screen of a display device using constantly changing moving position data and image information data, displaying on a map a first means for searching for a road along the traveling trajectory of a moving object to extract data on the searched road when the traveling trajectory of the moving object deviates from the road; A second means for comparing the travel trajectory data to determine similarity and selecting the road with the highest similarity among them, and displaying the travel trajectory on the selected road. a third means for correcting the data; and a third means for detecting a singular point that causes errors intensively and dividing the traveling trajectory according to the position;
A traveling position display device for a moving body, comprising: means for executing the third means for each of the divided traveling trajectories.