JPH0317687A - On-vehicle navigation device - Google Patents

Abstract

PURPOSE:To attract driver's attention by making a display when a vehicle travels in an area outside the range of map data or unless a storage medium is loaded when the necessary map data are read in. CONSTITUTION:A CD-ROM is stored with the map data obtained by digitizing respective points on roads in a map. A CD-ROM driver 10 reads the stored information out of the CD-ROM. The read output of the CD-ROM driver 10 is decoded by a CD-ROM decoder 11 and sent out to a bus line L. When no map disk is loaded on the CD-ROM driver 10, a CPU 7 drives and controls a display device 16 to display a message indicating that no disk is loaded on a display 17, thereby informing the driver that no map disk is loaded.

Description

[Detailed description of the invention] Technical field The present invention relates to an on-vehicle navigation device.

BACKGROUND ART In recent years, map data obtained by digitizing each point on a road on a map is stored in a storage medium such as a CD-ROM, and a map of a certain range of area including the current location is created while recognizing the current location of the vehicle. The data group is read from the storage medium and displayed on the display as a map around the vehicle's current location.
In-vehicle navigation devices that automatically display the vehicle's current location on the map are being developed and put into practical use.

In such an in-vehicle navigation device, there is a limit to the amount of data that can be stored in a storage medium, such as a CD-ROM, so that one CD-ROM can only store map data for a certain area. Therefore, while driving using navigation based on the map data of a CD-ROM that stores map data of a specific area, it is possible that the vehicle may drive in an area outside the range of the map data. In such a case, the map display suddenly disappears from the display. Also, when loading the necessary map data from the CD-ROM,
The same thing can be said when a CD-ROM is not installed in the CD-ROM driver.

SUMMARY OF THE INVENTION Therefore, the present invention provides an in-vehicle navigation device that can be used even when driving in an area outside the range of map data or when a storage medium is not installed when reading necessary map data. The purpose is to

In the in-vehicle navigation device according to the present invention, while recognizing the current location of the vehicle, the map data group of a certain area including the current location is read out from the storage medium and displayed as a map around the current location of the vehicle on the display. , when it is detected that the current location obtained by the vehicle's current location recognition is outside the area where the map data group is stored in the storage medium, or when it is detected that the storage medium is not attached to its reading means; It is configured to display the following.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing an embodiment of an in-vehicle navigation device according to the present invention. In the figure, 1 is a direction sensor for detecting the running direction of the vehicle using, for example, geomagnetism (earth's magnetic field), 2 is an angular velocity sensor for detecting the angular velocity of the vehicle, and 3 is a distance sensor for detecting the distance traveled by the vehicle. , 4 is a GPS (Global Position) for detecting the absolute position of the vehicle from latitude and longitude information, etc.
The detection output of each of these sensors (devices) is supplied to the system controller 5.

The system controller 5 connects to an interface 6 which processes the detection outputs of each sensor (device) 1 to 4 manually and processes such as A/D (analog/digital) conversion, and processes various image data and sequentially sends the data from the interface 6. A CPU (Central Processing Circuit) that calculates the vehicle's travel distance, travel direction, current location coordinates (longitude, latitude), etc. based on the output data of each sensor (device) 1 to 4.
7, a ROM (read-only memory) 8 in which various processing programs and other necessary information for the CPU 7 are written in advance, and a RAM (random memory) in which information necessary for executing programs is written and read.・Access ●Memory) 8.

As the external storage medium, a read-only nonvolatile storage medium such as a CD-ROM, and a writable and readable nonvolatile storage medium such as DAT (digital audio tape) are used. In addition,
The external storage medium is not limited to CD-ROM or DAT, but it is also possible to use a nonvolatile storage medium such as an IC card. The CD-ROM stores in advance map data obtained by digitizing (numerizing) each point on a road on a map. Information stored in this CD-ROM is read by a CD-ROM driver 10. CD-R
The read output of the OM driver 10 is decoded by the CD-ROM decoder 11 and sent to the bus line L.

On the other hand, the DAT is used as a so-called backup memory, and information is recorded or read by the DAT deck 12. When the vehicle power supply is cut off, information such as the current position coordinates of the vehicle stored in the RAM 9 immediately before is supplied to the DAT deck 12 via the DAT encoder/decoder 13 as backup data, and is stored in the DAT. DA for the introduction of
The stored information of T is read out by the DAT deck 12. The read information is sent to the DAT encoder/decoder 13
RAM by being sent to bus line L via
9 is stored.

Turning the vehicle power on and off is detected by a detection circuit 14 that monitors the output level of a so-called accessory switch SW of the vehicle. Vehicle power from a battery (not shown) that has passed through the accessory switch SW is stabilized by a regulator 15 and supplied as power to each part of the device. Due to the time constant of the circuit, the output voltage of the regulator 15 does not fall instantaneously when the accessory switch SW is turned off, and backup data is stored in the DAT as a backup memory during this falling period.

When the vehicle is running, the CPU 7 calculates the running direction of the vehicle based on the output data of the direction sensor 1 at a predetermined period by a timer interrupt, and calculates the running distance and The vehicle's current location coordinates are determined from the driving direction, map data of a certain range of area including the current location coordinates is collected from the CD-ROM, and this collected data is used as a buffer memory and the RA of
It is temporarily stored in M9 and supplied to the display device 16. As a method for determining the running direction of the vehicle based on the output data of the direction sensor 1, a method described in Japanese Patent Application Laid-Open No. 130013/1983 may be used.

The display device 16 includes a display 17 such as a CRT, and a V
(Video) - A graphic memory 18 consisting of RAM, etc., a graphic controller 19 that draws map data sent from the system controller 5 as image data in the graphic memory 18 and outputs this image data, and this graphic controller. Display 17 based on image data output from one
It is comprised of a display controller 20 that controls the display of a map on the top of the screen. The input device 21 consists of a keyboard or the like, and issues various commands and the like to the system controller 5 by the user's keystrokes.

Next, the processing procedure for display control of the display 17 executed by the CPU 7 will be explained along with the flowcharts in FIGS. 2A and 2B. In addition, this routine is performed when the accessory switch SW is turned on. It is assumed that it is called and executed when lSilli is input.

In FIG. 2A, the CPU 7 first initializes the hardware (step S1), and then loads the backup data stored in the DAT as a backup memory into the RAM 9 (step S2). DAT
The vehicle's current location coordinate data and the like at the time of power-off are stored as backup data. Next, the CPU
7 is a CD-ROM (hereinafter abbreviated as a map disk) in which map data is stored. First, map management information for managing each of the plurality of maps stored on the disk divided into certain regions is downloaded. A command to that effect is sent to the CD-ROM decoder 11 for reading (step S3). This allows the map disc to be transferred to CD-RO.
If it is installed in the M driver 10, the map management information is read from the map disk by the CD-ROM driver 10, the CD-ROM decoder 11 is discarded, and the map management information is stored in the RAM.
9 is stored. If an error message is returned from the CD-ROM decoder 11 in response to the command to read map management information, the CPU 7
It is determined that no map disk is attached to the computer (step S4).

If a map disk is not installed in the CD-ROM driver 10, the CPU 7 drives and controls the display device 16 to display a message such as ``No disk is installed.Insert the disk and press any key.'' .

'' is displayed on the display 17 to inform the driver that the map disc is not installed (step S5), and the system waits for the driver to press the key (step S6). Then, if there is key human power, the program returns to step S3. Note that a subroutine (not shown) of the key manual is called by the key manual, and the message is deleted by the process. On the other hand, if a map disk is installed in the CD-ROM driver 10, the CPU 7 determines whether the current location coordinates of the vehicle at the time of power-off were within the map range recorded on the map disk (step S7). This determination is made by comparing the current location coordinate data in the backup data and the coordinate data in the map management information.

If the current location at the time of power outage was within the map range,
The CPU 7 executes a process of reading a map data group of a certain range of area centered on the vehicle's current location coordinates from the Jtll map disk and storing it in the RAM 9 (step S8), and then steps 31. Move to 1. A map of a certain area is a unit map, and each drawing is numbered and map management data such as coordinate data defining the map range is stored.

A subroutine for executing map data reading processing will be described later. On the other hand, if the current location coordinates at the time of power-off are outside the map range, the CPU 7 again executes the map range check process based on the current location coordinates (step S9).
. A subroutine for executing this process will also be described later. In the map range check process, as will be described later, if there is no map where the current location coordinates are located, a process is performed in which the no map flag indicating this is turned ON, so after the check process, the no map flag on the CPU 7 is turned ON. It is determined whether or not (step S10). No map flag is O
If N, the program moves to step Sll, while if the no-map flag is OFF, that is, if there is a map where the current location coordinates are located, the program moves to step S8.

Here, the above-mentioned map data reading process (step S
8) and the map range checking process (step S9) will be explained with reference to the flowcharts of FIGS. 3 and 4.

First, in FIG. 3 showing a subroutine for reading map data, the CPU 7 determines necessary data from the current location coordinate data and drawing management data (step S31).
), and then it is determined whether the current location coordinates have gone outside the map range by comparing both data (step S32). If it goes outside the map range, the CPU 7 sets the no map flag to O.
N (step S33), and after L, the program is the second
The process moves to step Sll in figure A. On the other hand, if it is within the map range, the CPU 7 determines whether all the necessary data determined in step S31 are stored in the RAM 9 (step S34). If all the necessary data is on the RAM, the program moves to step Sll.

On the other hand, if there is no necessary data on the RAM, the CPU 7
To read the necessary data, enter the command to that effect on the CD-
Send to the ROM decoder 11 (step S35
). As a result, if the map disk is installed in the CD-ROM driver 10, the CD-ROM driver 1
0 reads the necessary data from the map disk,
It is stored in the RAM 9 via the CD-ROM decoder 11. CD-ROM for read command of necessary data
If an error message is returned from the decoder 11, C
In PU7, the map disk was removed midway and the CD-RO was removed.
It is determined that it is not attached to the M driver 10 (step S36). If the map disk is not installed, the CPU 7 sets the no-disk flag ONL (step S37), and then the program returns to the main routine. If the map disk is installed, the program proceeds directly to step Sll in FIG. 2A.

Next, in FIG. 4 showing a subroutine for checking the map range, the CPU 7 refers to the drawing management data of the drawing number indicated by the pointer, for example, the coordinate data of the four corners of the drawing (step S41), and determines the current location coordinates. is 4 in the drawing
It is determined whether it is within the coordinate range defined by the corner coordinate data (step S42). If the current location coordinates are within the coordinate range of the drawing specified by the pointer, the CPU 7 determines that the corresponding map exists and sets the drawing number etc. (step S43).
, after which the program moves to step S10 of FIG. 2A.

On the other hand, if the current location coordinates are outside the coordinate range of the drawing indicated by the pointer, the CPU 7 advances the pointer to the next drawing number (step S44), and then determines whether or not checking has been completed for all drawing numbers. Zuru (step S45). If all drawing numbers have not been checked, the program returns to step S41 and repeats the above-described process. In this case, the CPU 7 sets the no-map flag to ONL. (Step S46) After the L is completed, the program moves to step S10.

Next, the processing of the main routine after step Sll will be explained. The CPU 7 calculates the current location coordinates of the vehicle based on the output data of the direction sensor 1 and the distance sensor 3 (step S].1), then determines whether the no map flag is ON (step S12), and displays the map. None flag is O
If N, the same map range check process as in the subroutine of FIG. 4 is executed again based on the current location coordinates calculated in step Sll (step S13). After this check process, the CPU 7 again determines whether the no map flag is ON (step S14). No map flag is OFF
If so, the CPU 7 re-executes the same process as the subroutine shown in FIG. 3, which reads map data of a certain area around the vehicle's current location coordinates from the map disk and stores it in the RAM 9 (step S15). Next, it is determined whether the no-disc flag is ON (step S16).

If the no-disk flag is OFF, that is, if a map disk is attached to the driver 10, the CPU 7 corrects the current location of the vehicle to the nearest line segment (a road is represented by a connection of line segments) obtained from the map data. A so-called map matching process is executed (step S7). If it is determined in step S12 that the no map flag is OFF, the program directly proceeds to step S17.

Because the current location coordinates change due to map matching processing,
The CPU 7 reads the map data of a certain area centered on the corrected current location from the map disk and stores it in the RAM.
The same process as the subroutine of FIG. 3 stored in 9 is executed again [2 (step S18), and then it is determined whether or not the no-disk flag is ON (step 819). If the no-disc flag is OFF, that is, if a map disc is attached to the driver 10, the CPU 7 determines whether the current location coordinates are outside the map range (step S20). If the current location coordinates are within the map range, normal travel module processing is executed (step S21). A subroutine for executing the processing of the normal running module will be described later.

On the other hand, in step S14, the no map flag is ON,
That is, if it is determined by the map range check that there is no corresponding map, the CPU 7 executes a process of determining the direction of the area where the map data group exists and displaying the direction (step S22).

The processing procedure for displaying the direction of the area where this map data exists will be described below with reference to the flowchart of FIG. In this example, as shown in Fig. 6, the display screen area is divided into nine parts, and the current location coordinates are in the center area (
1.1), and the direction in which the map data group exists is displayed by color-coding the eight areas around it.

In addition, each area corresponds to one unit map, and its longitude,
Let the latitude range be (ΔX, ΔY), and the longitude and latitude of the vehicle's current location be (Xo, YO). On the other hand, map numbers n are assigned to the n maps, and map management information is stored in the memory area as shown in Figure 7, including longitude Xn+ of the left end and latitude X of the bottom end.
n+ It is assumed that other information is stored for each map.

First, the CPU 7 determines the longitude and latitude of the current location (Xo.Yo)
The longitude and latitude range of one unit map (ΔX, ΔY
) shifted leftward and downward by the display area (0,
Find the coordinates (X, Y) at O) (step S5
1, S52), then reset the count value k of the map number (step S53), and then the coordinates (X, Y) are the longitude and latitude range (xg to x+) + ΔX of map number 1,
! I/O ~ Yo + Δy) (S54, S55). Coordinates (X, Y)
If the map number 1 does not belong to the longitude and latitude range, the CPU
7 increments the count value k of the map number (S56), and then the count value k becomes the number of maps n.
It is determined whether or not it is less than or equal to (step S57). If k≦n, the program returns to step S54 and repeats the above-described process, that is, the process of determining whether there is a map to which the coordinates (X, Y) belong among the n maps. kin, that is, when there is no map to which the coordinates (x, y) belong among the n maps, the CPU 7 displays the display area (0
．． 0), for example, in black (step 858), and if there is a map to which the coordinates (x, y) belong, the display area (0, O) is displayed in red, for example. The display device 16 is driven and controlled (step 859).

When the presence or absence of the map data group has been displayed for the display area (0.0), the CPU 7 shifts the Y coordinate upward by ΔY (step S60), and then increments the count value j of the area number in the Y direction. (Step S61), and then it is determined whether j≦2 (Step S62).

If j≦2, the program returns to step S53 and performs the above-mentioned process, that is, the display areas (0.1) and (
0. Regarding 2), the process of determining the presence or absence of a map data group and displaying it is repeated.

If j>2, this means that the display of the presence or absence of the map data group has been completed for the three display areas in the Y direction at the left end, so the CPU 7 shifts the X coordinate to the right by ΔX (step S63), and then and increments the count value i of the area number in the X direction (step S64
), and then determines whether i≦2 (step S6
5). If i≦2, the program returns to step S52 and performs the above-mentioned process, that is, determines the presence or absence of a map data group in order for the three display areas in the middle Y direction and the three display areas in the rightmost Y direction. Moreover, the process of displaying the display is repeated.

If i>2, the program returns to the main routine.

Through the above processing, as shown in Fig. 8, on the display 17, directions for which map data exists are displayed in red, and directions for which map data does not exist are displayed in black, regarding eight directions centered on the own military position. The display will notify the driver of the direction of the area where the map data group exists. In this example, the display screen of the display 17 is divided into a plurality of areas centering on the position of the own army, and each area is displayed in a predetermined color to display the direction of the area where the map data group exists. The present invention is not limited to this, but the point is that it is sufficient to notify the driver of the direction of the area where the map data group exists based on the position of the own army.

In the main routine of FIG. 2B again, after the process of determining the direction in which the map data group exists and displaying the direction (step S22), or in step S16 or step S19, if the no-disk flag is turned ON,
That is, when it is determined that the map disk is not attached to the driver 10, the CPU 7 causes the display device 1 to display a message to that effect on the display 17.
6 (step 323), and then the process of the mapless travel module is executed (step S24). A subroutine for executing the process of the mapless travel module will be described later. If it is determined in step S20 that the current location coordinates are outside the map range, the program directly proceeds to step S24 and executes the process of the mapless travel module. After executing the processing of the normal driving module or the mapless driving module, the CPU 7 determines whether the vehicle power is turned off based on the output of the detection circuit 14 (step S25), and if the vehicle power is not turned off, the program moves to step S25. Returning to S11, the process of the above-described main routine (steps 811 to 25) is repeated, and if the vehicle power is turned off, the program ends the series of processes for navigation.

Next, a subroutine for processing the normal running module will be explained with reference to the flowchart shown in FIG. C
The PU 7 drives and controls the display device 16 so that the RA
A map centered on the own vehicle position is displayed on the display 17 based on the map data centered on the current location coordinates stored in M9 (step S91), and the driving direction obtained based on the output data of the direction sensor 1 is further displayed. Then, a travel trajectory obtained by disorganizing past current location coordinate data stored in the RAM 9 is displayed on a map (step S92).

The program then returns to the main routine.

Next, a subroutine for processing the mapless travel module will be explained according to the -7 flowchart in FIG. First, the CPU 7 connects the interface 61:GP
Determine whether or not the S device 4 is connected (step S
IOI), if GPS device 4 is connected, GPS
Output data of device 4 (hereinafter abbreviated as GPS data)
The current location of the vehicle is estimated based on the aPIL (step S102), a message to that effect is displayed on the display 17 (step 8103), and the driving direction and the driving trajectory, etc. are displayed on the display 17. (Surokutsubu S 1 04). At the same time, a display indicating that the vehicle is traveling outside the map range may be displayed.

After processing this display mode, the program returns to the main routine. If the GPS device 4 is not connected, the current depression of the vehicle is estimated based on the output data of the direction sensor 1 and the distance sensor 3 (step S105), and after completing the L calculation, the program moves to step S104.

Here, the processing procedure of the display mode of the traveling direction, traveling trajectory, etc. in the mapless traveling module will be explained according to the flowchart of FIG. 11. Note that the display of the running direction and the running trajectory is performed by superimposing the base screen on a window screen including the own army mark indicating the vehicle's current location coordinates and running direction, as shown in FIG.

First, the CPU 7 determines the running direction and distance of the vehicle based on the output data of the direction sensor 1 and the distance sensor 3 (step Sll). The driving direction will be displayed as one of the plurality of patterned display directions, and since the plurality of display directions are numbered, C
The PU 7 converts the obtained traveling direction (X, Y) into the corresponding direction number (step S112), further converts the obtained traveling distance into a buffer coordinate value corresponding to the display scale, and uses the converted value to display the data on the buffer. Movement displacement (ΔX, ΔY
) is calculated (step 8 1 1 3).

Next, the CPU 7 instantly redraws the direction display on the window screen based on the direction number (step Sll4), and uses the movement displacement (ΔX, ΔY) to change (scroll) the display position of the window screen on the base screen. (Step S
115), and additionally draws a travel trajectory mark at the current location coordinates on the base screen at the new display position (step S11).
6). Thereafter, the program returns to the subroutine of FIG.

In this example, the traveling direction and the traveling trajectory are displayed together, but it is also possible to display only the traveling direction.

Effects of the Invention As explained above, the T4i-based navigation device according to the present invention recognizes the current location of the vehicle, reads out map data of a certain area including the current location from the storage medium, and displays the vehicle on the display. When displaying a map around the current location, when it is detected that the current location obtained by the vehicle's current location recognition is outside the area where the map data group is stored in the storage medium, or fc
! When it is detected that the storage medium is not attached to the reading means, a display to that effect is displayed. As a result, if the map display suddenly disappears from the display while driving, the driver can use the display to determine whether the driver is driving in an area outside the range of the map data or whether the storage medium is not installed. For example, if a storage medium is not installed, it is possible to quickly respond by installing a storage medium.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the in-vehicle navigation device according to the present invention, FIGS. 2A and 2B are a flowchart showing the procedure for display control, and FIG. 3 is a flowchart showing the procedure for reading map data. , Fig. 4 is a flowchart showing the procedure for checking the map range, Fig. 5 is a flowchart showing the processing procedure for determining the direction in which map data exists and its display mode, and Fig. 6 is a flowchart showing the processing procedure for determining the direction in which map data exists. Figure 7 is a diagram showing an example of a memory area map for map management information, Figure 8 is a diagram showing an example of the configuration of the screen area for map management information, and Figure 8 is a case where the direction where map data exists is displayed in red and black colors. Figure 9 is a flowchart showing the processing procedure of the normal travel module, Figure 10 is a flowchart showing the processing procedure of the mapless travel module, and Figure 11 is the travel direction and travel trajectory in the mapless travel module. FIG. 12 is a flowchart showing the processing procedure of the display mode, and FIG. 12 is a diagram showing the display state of the driving direction and the driving trajectory in the mapless driving module. Explanation of symbols of main parts 1... Orientation sensor 3... Distance sensor 4... GPS device 5... System controller 10... CD -ROM driver 12...
...DAT deck 16...Display device 17
······display

Claims (2)

[Claims] (1) A display means for displaying an image according to a supplied display information signal, and a reading device for reading a plurality of map data groups from a storage medium storing a plurality of map data groups each corresponding to a divided area within a predetermined area. means, controlling to extract from the storage medium a group of map data of a certain area including the current location of the vehicle while recognizing the current location of the vehicle, and supplying the extracted map data group to the display means as the display information signal; An in-vehicle navigation device is provided with a control means for displaying a map around the current location of the vehicle, wherein the control means detects that the current location obtained by recognizing the current location of the vehicle is outside the predetermined area; An in-vehicle navigation device characterized in that when it is detected that a storage medium is not attached to the reading means, a display information signal is supplied to the display means to display a message to that effect. (2) The in-vehicle navigation device according to claim 1, wherein the reading means includes a buffer memory that stores the map data group read from the storage medium.