JPH0782291B2 - Car navigation system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle-mounted navigation device.

BACKGROUND ART In recent years, map data obtained by digitizing each point on the road of a map is stored in a storage medium such as a CD-ROM, and while recognizing the current location of a vehicle, a map of a certain area including the current location A vehicle-mounted navigation device has been developed and put into practical use, which reads out a data group from a storage medium and displays it on a display as a map around the current location of a vehicle, and automatically displays the vehicle position indicating the current location of the vehicle on the map.

In such a vehicle-mounted navigation device, since the amount of data that can be stored in, for example, a CD-ROM as a storage medium is limited, one CD-ROM can store only map data of a certain area. For this reason, it is possible that a vehicle may travel in an area outside the range of the map data while traveling by the navigation based on the map data of the CD-ROM that stores the map data of the specific area. In such a case, the map display will suddenly disappear from the display.

SUMMARY OF THE INVENTION Therefore, it is another object of the present invention to provide an in-vehicle navigation device that can handle a case where the vehicle travels in an area outside the range of map data.

The on-vehicle navigation device according to the present invention is configured to display the map data from a display medium that displays an image according to the supplied display information signal and a storage medium that stores a plurality of map data groups respectively corresponding to divided areas within a predetermined area. A reading unit for reading a group and a recognition process for recognizing the current position of the vehicle are performed, and the reading unit is controlled so as to extract a map data group of a predetermined area including the recognized current position obtained from the reading process from the storage medium. And a vehicle-mounted navigation device comprising a control means for supplying the extracted map data group to the display means as the display information signal and displaying it as a map of the vicinity of the current location of the vehicle, wherein the control means indicates that the recognized current location is When it is detected that the vehicle is outside the predetermined area, a map data group exists on the display screen with the current position of the vehicle as a reference. It is characterized by supplying the display information signal to said display means to form a direction display indicating the direction of the band.

That is, according to the vehicle-mounted navigation device of the present invention,
When it is detected that the current location obtained by the recognition process exceeds the map range defined by all the map data stored in the storage medium, the direction of the area in which the map data group exists is displayed.

Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a vehicle-mounted navigation device according to the present invention. In the figure, 1 is an azimuth sensor for detecting the traveling azimuth of the vehicle by, for example, geomagnetism (earth 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 traveling distance of the vehicle. 4 is a GPS (Global Positioning System) for detecting the absolute position of the vehicle from latitude and longitude information.
The output of each of these sensors (devices) is supplied to the system controller 5.

The system controller 5 receives the detection outputs of the sensors (devices) 1 to 4 as an input and performs an A / D (analog / digital) conversion process and the like, and various image data processes and is sequentially sent from the interface 6. Based on the output data of the respective sensors (devices) 1 to 4, the traveling distance, traveling direction, and current position coordinates (longitude,
A CPU (central processing circuit) 7 for performing calculations such as latitude), a ROM (read only memory) 8 in which various processing programs of the CPU 7 and other necessary information are written in advance,
RAM (Random Access Memory) 8 where information necessary for executing the program is written and read
It is configured.

As each unit storage medium, for example, a CD-ROM as a read-only non-volatile storage medium, and as a writable and readable non-volatile storage medium such as a DAT (digital
Audio tape) is used. The external storage medium is not limited to a CD-ROM or DAT, and a non-volatile storage medium such as an IC card can be used. The CD-ROM stores in advance map data obtained by digitizing (numericalizing) each point on the road of the map. This CD-RO
The information stored in M is read by the CD-ROM driver 10. The read output of the CD-ROM 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 recording or reading of information is performed by the DAT deck 12
Done by. Immediately before turning off the vehicle power
Information such as the vehicle's current position coordinates stored in RAM9 is stored as backup data in the DAT by being supplied to the DAT deck 12 via the DAT encoder / decoder 13, and when the vehicle power is turned on, the stored DAT information is stored in the DAT. Deck 12
Read by. The read information is stored in the RAM 9 by being sent to the bus line L via the DAT encoder / decoder 13.

The turning on and off of the vehicle power is detected by the detection circuit 14 which monitors the output level of the 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 the regulator 15 and supplied as power to each part of the device. The output voltage of the regulator 15 does not fall instantaneously when the accessory switch SW is turned off due to the time constant of the circuit, and backup data is stored in the DAT as a backup memory during this fall period. .

When the vehicle is traveling, the CPU 7 calculates the traveling azimuth of the vehicle based on the output data of the azimuth sensor 1 at a predetermined cycle by a timer interruption, and the traveling distance and the traveling distance by interruption every constant distance traveling based on the output data of the distance sensor 3. Obtain the coordinates of the current position of the vehicle from the traveling direction, collect map data of a certain range of areas including the coordinates of the current position from the CD-ROM, and temporarily store the collected data in the RAM 9 as a buffer memory and on the display device 16. Supply. As a method for obtaining the traveling direction of the vehicle based on the output data of the direction sensor 1, the method described in JP-A-62-130013 can be used.

The display device 16 includes a display 17 such as a CRT and a V (Video).
A graphic memory 18 including a RAM, a graphic controller 19 for drawing map data sent from the system controller 5 as image data in the graphic memory 18, and outputting the image data; and a graphic controller 19 for outputting the graphic data. The display controller 20 controls to display a map on the display 17 based on the image data. The input device 21 is composed of a keyboard and the like, and issues various commands to the system controller 5 by key input by the user.

Next, the processing procedure of the display control of the display 17 executed by the CPU 7 will be described with reference to the flowcharts of FIGS. 2A and 2B. It should be noted that this routine is called and executed when the vehicle power is turned on by turning on the accessory switch SW.

In FIG. 2A, the CPU 7 first initializes the hardware (step S1), and then the backup data stored in the DAT as the backup memory is transferred to the RAM 9
(Step S2). The DAT stores the current position coordinate data of the vehicle when the power is cut off as backup data. Subsequently, the CPU 7 manages each of a plurality of maps which are recorded on the disc from a CD-ROM (hereinafter, abbreviated as a map disc) in which map data is stored and which are divided into a certain area. A command to that effect is sent to the CD-ROM recorder 11 to read the management information (step S3). Thus, if the map disk is loaded in the CD-ROM driver 10, the CD-COR driver 10 reads the map management information from the map disk and stores it in the RAM 9 via the CD-ROM decoder 11. CD-ROM for command to read map management information
If the error message is returned from the decoder 11, CPU7
Determines that the map disk is not loaded in the CD-ROM driver 10 (step S4).

When the map disk is not installed in the CD-ROM driver 10, the CPU 7 drives and controls the display device 16 to display, for example, "The disk is not installed. Please install the disk and press any key. Message is displayed on the display 17 to inform the driver that the map disk is not mounted (step S5), and key input is performed (step S6). Then, if there is a key input, the program returns to step S3. By the key input, a key input subroutine (not shown) is called, and the message is erased by the processing. on the other hand,
If the map disk is loaded in the CD-ROM driver 10, the CPU 7 determines whether or not the coordinates of the current position of the vehicle at the time of power off are within the map range recorded in the map disk (step S7). This determination is made by comparing the current position coordinate data in the backup data with the coordinate data of the map management information.

If the current coordinates at the time of power off are within the map range,
The CPU 7 executes a process of reading a map data group of a certain area centering on the current position coordinates of the vehicle from the map disk and storing it in the RAM 9 (step S8), and then the step S1.
Move to 1. A map of an area within a certain range is a unit map, and map management data such as coordinate data that is numbered for each drawing and defines the map range is stored. The subroutine for executing the map data reading process will be described later. On the other hand, when the current position coordinates at the time of power off are outside the map range, the CPU 7 executes the map range check process again based on the current position coordinates (step S9). A subroutine for executing this processing will also be described later. In the map range check process, if there is no map where the current position coordinates are located, the no map flag is turned on
After the check processing, the CPU 7 determines whether or not this mapless flag is ON (step S10). If the mapless flag is ON, the program proceeds to step S11 while the mapless flag is set to O.
If there is a map where FF, that is, the current position coordinates,
The program moves to step S8.

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

First, in FIG. 3 showing a subroutine for performing a process of reading map data, the CPU 7 determines necessary data from the current position coordinate data and the drawing management data (step S31), and subsequently, by comparing both data, the current position coordinate is the map range. It is determined whether or not the user has gone outside (step S32). When outside the map range, the CPU 7 turns on the mapless flag (step S33), and then the program proceeds to step S11 in FIG. 2A. On the other hand, if it is within the map range, the CPU 7 determines whether or not all the necessary data determined in step S31 are stored in the RAM 9 (step S34). If all the necessary data is in RAM, the program proceeds to step S11.
Move to.

On the other hand, when there is no necessary data in the RAM, the CPU 7 sends a command to that effect to the CD-ROM decoder 11 to read the necessary data (step S35). As a result, if the map disk is installed in the CD-ROM driver 10, the CD-ROM driver 10 reads the necessary data from the map disk, and the CD-ROM data 11 reads the R data.
It is stored in AM9. If an error message is returned from the CD-ROM data 11 in response to the necessary data read command, the CPU 7 will remove the map disk in the middle and
It is determined that the driver 10 is not installed (step
S36). CPU if no map disk is installed
7 turns on the diskless flag (step S37), after which the program returns to the main routine. If the map disk is loaded, the program proceeds directly to step S11 in FIG. 2A.

Next, in FIG. 4 showing a subroutine for performing the process of checking the map range, the CPU 7 refers to the drawing management data of the drawing number designated by the pointer, for example, the coordinate data of the four corners of the drawing (step S41), and coordinates the current position. Is within the coordinate range defined by the coordinate data of the four corners of the drawing (step S42). If the coordinates of the current location are within the coordinate range of the drawing designated by the pointer, the CPU 7 determines that there is a corresponding map and sets the drawing number and the like (step V43), and then the program proceeds to step S10 in FIG. 2A.

On the other hand, if the current position coordinates are outside the coordinate range of the drawing designated by the pointer, the CPU 7 advances the pointer to the next drawing number (step S4
4) Then, it is judged whether or not the check is completed for all the drawing numbers (step S45). If all the drawing numbers have not been checked, the program will
The process returns to S41 and the above process is repeated. If all the map numbers have been checked, it means that there is no corresponding map, so the CPU 7 turns on the mapless flag (step S4
6) Then, the program shifts to step S10.

Next, the processing of the main routine after step S11 will be described. The CPU 7 calculates the current position coordinates of the vehicle based on the output data of the azimuth sensor 1 and the distance sensor 3 (step S11), and subsequently determines whether or not the mapless flag is ON (step S12). If it is ON, the same map range checking process as the subroutine of FIG. 4 is executed again based on the current position coordinates calculated in step S11 (step S13). After this check processing, the CPU 7 determines again whether or not the mapless flag is ON (step S14).
If the no map flag is OFF, the CPU 7 again executes the same processing as the subroutine of FIG. 3 for reading the map data of the area within a certain range centered on the current position coordinates of the vehicle from the map disk and storing it in the RAM 9 (step S15), and subsequently it is determined whether or not the diskless flag is ON (step S1).
6). If the disk-less flag is OFF, that is, if the map disk is installed in the driver 10, the CPU 7 corrects the current location of the vehicle on the nearest line segment (a road is represented by a line segment) obtained from the map data. A so-called map matching process is executed (step S17). Step S12
When it is determined that the no map flag is OFF in, the program directly proceeds to step S17.

Since the current location coordinates change due to the map matching process,
The CPU 7 again executes the same processing as the subroutine of FIG. 3 for reading the map data of the area within a certain range centered on the corrected current position coordinates from the map disk and storing it in the RAM 9 (step S18), and then the disk-less flag. It is determined whether or not is ON (step S19). No disk flag is OFF,
That is, if the map disk is attached to the driver 10, the CPU 7 determines whether the current position coordinates are outside the map range (step S20). If the current position coordinates are within the map range, the normal traveling module processing is executed (step S2).
1). The subroutine for executing the processing of the normal traveling module will be described later.

On the other hand, in step S14, if the no map flag is ON, that is, if it is determined that there is no corresponding map by the map range check, the CPU 7 determines the direction of the area in which the map data group exists and executes the process of displaying the direction. Yes (step S22). The processing procedure for displaying the direction of the area where the 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, for example, nine areas, the current position coordinates belong to the central area (1,1), and the eight areas around the map data are color-coded. The direction in which the group exists shall be displayed. Each area corresponds to one unit map, and its longitude and latitude range is (ΔX, ΔY), and the longitude and latitude of the current position of the vehicle are (X ₀ , Y ₀ ). On the other hand, the map number n is attached to the n maps, and the left end longitude xn, the lower end latitude yn, and other information are stored for each map in the memory area as map management information as shown in FIG. Be present.

First, the CPU 7 displays a display area (0,0) shifted leftward and downward by a longitude and latitude range (ΔX, ΔY) of one unit map with respect to the longitude and latitude (X ₀ , Y ₀ ) of the current location. The coordinate (X, Y) at is calculated (steps S51, S52), the count value k of the map number is subsequently reset (step S53), and then the coordinate (X, Y) is the longitude / latitude range of the map number 1 ( x ₀ ~x ₀ +
_{Δx, y 0 ~y 0 + Δy} ) to determines whether or not belonging (step S54, S55). If the coordinate (X, Y) does not belong to the longitude / latitude range of the map number 1, the CPU 7 increments the count value k of the map number (step S56), and then the count value k is less than or equal to the number of maps n. (Step S5
7). If k ≦ n, the program returns to step S54 to perform the above-mentioned processing, that is, coordinates (X, Y) in n maps.
The process of determining whether or not there is a map to which is belongs is repeated. k> n
In the case of, that is, when there is no map to which the coordinates (X, Y) belong in the n maps, the CPU 7 drives and controls the display device 16 to display the display area (0,0) in black, for example. (Step S58) If there is a map to which the coordinates (X, Y) belong, the display area (0,0) is drive-controlled to display the display device 16 in red, for example (Step S59).

When the display of the presence or absence of the map data group for the display area (0,0) is completed, the CPU 7 shifts the Y coordinate upward by ΔY (step S60), and then increments the count value j of the Y direction area number. (Step S6
1) Then, it is determined whether j ≦ 2 (step S6).
2). If J ≦ 2, the program returns to step S53 to perform the above-mentioned processing, that is, display areas (0,1) and (0,2).
With respect to, the process of determining the presence or absence of the map data group and displaying it is repeated. If j> 2, it means that the presence / absence display 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 continues. Then, the count value i of the area number in the X direction is incremented (step 64), and then it is determined whether i ≦ 2 (step S65). If i ≦ 2, the program returns to step S52 and determines the presence / absence of the map data group in the order of the above-mentioned processing, that is, the three display areas in the middle Y direction and the three display areas in the rightmost Y direction. And the process of forming the display is repeated. i> 2
If so, the program returns to the main routine.

By the above processing, as shown in FIG.
The direction on which map data exists for the eight directions centering on the position of the vehicle is displayed in red on the 17 side, and the direction for which map data does not exist is displayed in black for discriminating display. Will be able to inform the driver. In this example, the display screen of the display 17 is divided into a plurality of areas centered on the vehicle position, and each area is displayed in a predetermined color to display the direction of the area in which the map data group exists. However, the present invention is not limited to this, and the point is that the driver can be notified of the direction of the area in which the map data group exists based on the vehicle position.

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, the no disk flag is ON, that is, the map disk If it is determined that the driver has not been installed in the driver 10, the CPU 7 drives and controls the display device 16 to display a message to that effect on the display 17 (step S23), and then the processing of the mapless traveling module is performed. Execute (step S24). The subroutine for executing the processing of the mapless traveling module will be described later. Step
If it is determined in S20 that the current position coordinates are outside the map range, the program directly proceeds to step S24 and executes the process of the mapless traveling module. After executing the processing of the normal traveling module or the mapless traveling module, the CPU 7 determines whether or not the vehicle power source is cut off based on the output of the detection circuit 14 (step S25). Returning to S11, the processing of the main routine (steps S11 to S25) described above is repeated, and if the vehicle power is off, the program ends the series of processing for aviation.

Next, a sub-routine for the processing of the normal traveling module will be described with reference to the flowchart of FIG. CP
The U7 drives and controls the display device 16 to display a map centered on the own vehicle position on the display 17 based on the map data centered on the current position coordinates stored in the RAM 9 (step S91) and further The traveling direction obtained based on the output data of the sensor 1 and the traveling locus obtained based on the past current position coordinate data accumulated in the RAM 9 are displayed on the map (step S92). Then the program returns to the main routine.

Next, the subroutine that performs the processing of the mapless traveling module will be described with reference to the flowchart of FIG. The CPU 7 first determines whether or not the GPS device 4 is connected to the interface 6 (step S101), and if the GPS device 4 is connected, the output data of the GPS device 4 (hereinafter abbreviated as GPS data). The current position of the vehicle is estimated based on only (step S102), a message to that effect is displayed on the display 17 (step S103), and then the traveling direction and traveling locus are displayed on the display 17 (step S104). . At this time, at the same time, a display indicating that the vehicle is traveling outside the map range may be displayed. After processing in this display mode, the program returns to the main routine. GPS
If the device 4 is not connected, the current position of the vehicle is estimated based on the output data of the azimuth sensor 1 and the distance sensor 3 (step S105), and the program thereafter proceeds to step S1.
Move to 04.

Here, the processing procedure of the display mode of the traveling azimuth and the traveling locus in the mapless traveling module will be described with reference to the flowchart of FIG. Note that the display of the traveling direction and the traveling locus is performed by superimposing a window screen including the own vehicle mark indicating the current position coordinates and traveling direction of the vehicle and the base screen, as shown in FIG.

First, the CPU 7 obtains the traveling azimuth and traveling distance of the vehicle based on the output data of the azimuth sensor 1 and the distance sensor 3 (step S111). The traveling azimuth will be displayed as one azimuth of a plurality of patterned display azimuths,
Since a plurality of display methods are numbered, the CPU 7 converts the obtained traveling azimuth (X, Y) into the corresponding azimuth number (step S112), and further the obtained traveling distance corresponds to the display scale. Is converted into a buffer coordinate value and the displacement (ΔX, ΔY) on the buffer is calculated from the converted value (step S113). Subsequently, the CPU 7 redraws the azimuth display of the window screen according to the azimuth number (step S114), and changes (scrolls) the display position of the window screen on the base screen by moving displacement (ΔX, ΔY) (step S1).
15) Further, the running trajectory mark is additionally drawn at the current position coordinates on the base screen at the new display position (step S116). After that, the program returns to the subroutine of FIG. In this example, the traveling direction and the traveling locus are displayed together, but it is also possible to display only the traveling direction.

As described above, according to the vehicle-mounted navigation device of the present invention, it is detected that the current position obtained by the recognition process exceeds the map range defined by all the map data stored in the storage medium. When this is done, the direction of the area where the map data group exists is displayed, which allows the driver to see the display and drive through the area where the map data group exists to display the map on the display. Therefore, even if it is a little detour to the destination, it is possible to drive while confirming the current location on the map, which is particularly useful when the route to the destination is not guided.

[Brief description of drawings]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Akiyama 25 Nishimachi, Kawagoe City, Saitama Prefecture 1 Nishimachi, Pioneer Corporation Kawagoe Factory (56) Reference JP-A-61-290476 (JP, A) JP Patent Sho 58-199376 (JP, A)

Claims (2)

[Claims] 1. A map data group is read from a display means for displaying an image according to a supplied display information signal and a storage medium storing a plurality of map data groups respectively corresponding to divided areas within a predetermined area. The reading means is controlled so as to extract the map data group of the area within the predetermined range including the recognized current position obtained from the reading means and the recognition process for recognizing the current position of the vehicle, and the extracted map. An in-vehicle navigation device comprising: a control means for supplying a data group to the display means as the display information signal and displaying it as a map around a current location of a vehicle, wherein the control means has the recognized current location outside the predetermined area. When it is detected, the direction display showing the direction of the area where the map data group exists on the display screen based on the current position display position of the vehicle. Vehicle navigation apparatus and supplying a display information signal to said display means to make. 2. The display means is capable of dividing the display screen into a plurality of areas centering on the current position display position and performing color display in area units, and the control means displays map data on the display screen. 2. The vehicle-mounted navigation device according to claim 1, wherein a color display information signal is supplied to the display means to display an area in the existing direction in a predetermined color.