JPH0778670B2 - 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 an area within a certain range 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.

When the vehicle travels using such an on-vehicle navigation device, the travel locus data is stored and held in the memory,
By displaying the traveling locus on the display based on the stored data when necessary, it is very convenient because it helps to confirm the past traveling route or the opposite route and to travel the same route next time.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vehicle-mounted navigation device that can easily display past travel paths on a display and can be used for route guidance.

In the vehicle-mounted navigation device according to the present invention, while recognizing the current position of the vehicle, the point data group indicating the point coordinates of the current position is collected according to the traveling of the vehicle and sequentially stored in the storage means, and the display command of the traveling path of the vehicle is issued. In response to this, the storage point data group of the storage means is sequentially read out in the storage order or the reverse order thereof, and the map data group including the point coordinates by the read out point data group is controlled to be extracted from the storage medium and the extracted map data group is extracted. By supplying the read point data group to the display means, the traveling locus is displayed while sequentially displaying a map of an area within a certain range including the point coordinates by the read point data group.

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 consists of and.

As the external storage medium, a read-only non-volatile storage medium such as a CD-ROM and a writable and readable non-volatile storage medium such as a DAT (digital audio tape) are 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 contains
Map data obtained by digitizing (numerizing) each point on the road of the map is stored in advance. This CD-ROM is a CD
-The ROM driver 10 reads the stored information. The read output of the CD-ROM driver 10 is the CD-ROM decoder 11
Is decoded by and transmitted 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 the 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 interrupt, and the traveling distance and The present position coordinates of the vehicle are obtained from the traveling direction, the map data of a certain area including the present position coordinates is collected from the CD-ROM, and the collected data is temporarily stored in the RAM 9 as the buffer memory and displayed on the display device 16. Supply. As a method for determining the traveling direction of the vehicle based on the output data of the direction sensor 1, the method described in Japanese Patent Laid-Open No. 63-11809 can be used.

The display device 16 includes a display 17 such as a CRT and a V (Video).
-Graphic memory 18 including RAM and the like, graphic controller 19 that draws map data sent from system controller 5 as image data in graphic memory 18 and outputs this image data, and output from this graphic controller 19 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 or the like including a locus key for issuing a traveling locus display command, and issues various commands such as a traveling locus display command to the system controller 5 by key input by a user.

Next, a processing procedure for collecting travel locus data executed by the CPU 7 will be described with reference to the flowchart of FIG. Note that this subroutine recognizes the current location of the vehicle every time the vehicle travels a certain distance da, reads out a map data group of a certain area including the current location from the CD-ROM, and displays it on the display 17 as a map around the current location of the vehicle. At the same time, it is assumed that the main routine (not shown) for displaying the current position of the vehicle on the map is called and executed at a predetermined timing during execution.

First, the CPU 7 determines whether or not the vehicle has traveled a certain distance db (≧ da) based on the output data of the distance sensor 3 (step S21). If the vehicle has traveled a certain distance, the current location of the vehicle is recognized. Store the obtained point coordinates of the current location and the point data group such as the map number including the coordinates in the address area designated by the write address pointer of the ring buffer in RAM 9 (step S22), and then write the address pointer. Advance by one data group (step S2
3).

By repeating this processing every time the vehicle travels a certain distance db, a number of spot data groups corresponding to the storage capacity are sequentially stored in the ring buffer as travel locus data. The traveling locus data is updated to new traveling locus data in order. When storing the traveling locus in the ring buffer, the traveling locus data may be sequentially stored in all the storage areas of the ring buffer, and a start address and an end address of a specific area of the ring buffer may be separated by a pointer. The travel locus data may be sequentially stored in the area defined and designated by the delimiter pointer.

Next, a processing procedure for displaying the traveling locus executed by the CPU 7 when a traveling locus display command is issued by a key input on the input device 21 will be described with reference to the flowchart of FIG.

The CPU 7 first responds to the key input command from the input device 21,
For example, the read address pointer is set to the address where the point data group of the starting point of the traveling locus is stored (step S31), the point data group is read from the ring buffer (step S32), and then the point by the read point data group is set. A buffer memory (eg, graphic memory 18) for a map data group of a certain area centered on the coordinates
The display device 16 is controlled to display the map and the point coordinates on the display 17 with the cursor (step S3
3) Then, the read address pointer is advanced by one data group (step S34).

Subsequently, the CPU 7 determines whether the read address pointer matches the write address pointer (step S3
5) If both pointers do not match, then it is determined whether the read address pointer matches the previous delimiter pointer (step S36). If the read address pointer does not match with the write address pointer or the delimiter pointer, it means that the traveling locus is not displayed up to the final traveling point, so that the vehicle waits for a certain time (step S3
7) Then, the program shifts to step S32. The reason for waiting for a certain time in step S37 is to scroll the map at the cycle of the time.

By repeating the above processing, the point data group is sequentially read from the ring buffer, and the map is scrolled on the display 17 so that the coordinate position of the point based on this point data group becomes the center and the traveling locus is displayed. It will be. Then, if the read address pointer matches the write address pointer or the delimiter pointer, it means that the display of the traveling locus has been performed up to the final traveling point, so the CPU 7 performs a series of processing for displaying the traveling locus. finish.

In the above embodiment, the point data group is read in the order stored as the traveling locus data in the ring buffer and the traveling loci are sequentially displayed from the start point to the end point, but in step S31 the read address pointer is set to the end point address. By setting and returning the read address pointer by one data group in step S34, the point data group is read in the reverse order of the storage order and the traveling locus is sequentially displayed from the end point to the start point. Is also possible.

As described above, in the vehicle-mounted navigation device according to the present invention, while recognizing the current position of the vehicle, the point data group indicating the point coordinates of the current position is collected according to the traveling of the vehicle and sequentially stored in the storage means. Every time, in response to the display command of the traveling locus of the vehicle, the storage point data group of the storage means is sequentially read out in the storage order or in the reverse order, and the map data group including the point coordinates by the read out point data group is extracted from the storage medium. By appropriately controlling and supplying the extracted map data group and the read-out point data group to the display means, the traveling locus is displayed while sequentially displaying a map of an area within a certain range including point coordinates by the read-out point data group. Therefore, you can easily display the past travel path on the display, and check the past travel route or the reverse route. Or, it will be useful for giving directions when driving on the same route next time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle-mounted navigation device according to the present invention, FIG. 2 is a flow chart showing a processing procedure for collecting travel locus data executed by a CPU, and FIG. 3 is a travel executed by the CPU. It is a flow chart which shows the processing procedure of display of a locus. Explanation of symbols of main parts 1 ... Direction sensor, 3 ... Distance sensor 5 ... System controller 10 ... CD-driver 16 ... Display device, 17 ... Display

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Akiyama 25 Nishimachi, Kawada City, Saitama Prefecture 1 Nishimachi, Pioneer Co., Ltd. Kawagoe factory (56) Reference JP-A-63-295915 (JP, A) Sho 63-11809 (JP, A) JP-A-59-204081 (JP, A)

Claims (2)

[Claims] 1. A display means for displaying an image according to a supplied display information signal and a reading means for reading the map data group from a storage medium storing a plurality of map data groups respectively corresponding to a plurality of regions. A current location recognizing means for recognizing the current location of the vehicle and obtaining a location data group indicating the location coordinates of the current location; and a location data collecting means for collecting the location data group according to the traveling of the vehicle and sequentially storing it in the storage means, And a traveling locus display means for displaying a traveling locus by the display means based on a storage point data group of the storage means in response to the display instruction. The locus display means controls, in response to the display command, to sequentially read the storage spot data group of the storage means in the storage order or the reverse order thereof. And a step of controlling the map data group including the point coordinates by the read point data group from the storage means to be extracted from the storage medium, and displaying the extracted map data group and the read point data group on the display means. A vehicle-mounted navigation device, comprising: a display control unit that supplies a signal and sequentially displays a map of a certain range including the read-out point data group while displaying a traveling locus. 2. The reading means includes a buffer memory for storing the map data group read from the storage medium, and the display control means stores the map data group centered on the point coordinates by the read point data group in the buffer memory. The in-vehicle navigation device according to claim 1, wherein the in-vehicle navigation device is controlled to be extracted from the vehicle.