JPH0333265B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an in-vehicle navigation device in which a departure point, a destination, and the current position of a vehicle are displayed on a display such as a cathode ray tube using respective marks.

[Prior art]

Conventional in-vehicle navigation devices, such as those disclosed in Japanese Patent Application Laid-open No. 146814/1983, detect the distance traveled and the heading direction of the vehicle, and calculate the traveling position of the vehicle from this information. On the other hand, the image information of the map read from the storage device is displayed on a display device such as a cathode ray tube, and
2. Description of the Related Art A device has been proposed that allows the user to know the current location of a vehicle on a map displayed on the screen of a display device by displaying a mark indicating the calculated current location of the vehicle.

However, map image information has a very large amount of information, and there is a limit to the amount of information that can be stored in a small, inexpensive storage device suitable for in-vehicle use.

Furthermore, in cases where the starting point and destination point are fixed, even if a map previously prepared in the storage device is displayed on the screen of the display device and a mark of the current location is superimposed on it, the actual The change in the running position is often in a very limited portion of the display screen.

Furthermore, when the distance between the starting point and the destination point is large, multiple maps are used, making it difficult to understand the entire driving process.

Although these technical issues are not necessarily impossible with large-capacity storage devices and high-speed arithmetic units, the overall scale of the devices has become increasingly large, making it difficult to install them in vehicles.

[Summary of the invention]

This invention was made with the purpose of improving such drawbacks.The storage means stores not the image information of the map itself, but the place names and their geographical coordinates, and the starting point and destination are stored by the input means. By specifying the place name of a point, the control means reads the coordinates of that point from the storage means, displays marks indicating the starting point and destination point on the display means at an appropriate scale, and displays the vehicle's current position accordingly. To propose an in-vehicle navigation device that displays a mark indicating the starting point and the destination point, and has a practically sufficient navigation function using a small and inexpensive storage device and arithmetic device. It is.

[Embodiments of the invention]

Embodiments of the in-vehicle navigation device of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, in which a traveling distance detecting means 101 detects the traveling distance of the vehicle, and a traveling direction detecting means 10 detects the traveling direction of the vehicle.
2. Mileage distance obtained by the current position initial setting means 104 that initializes the current position;
The current position of the vehicle is calculated by the current position calculation means 103 from the traveling direction and the current position initial setting values.

On the other hand, a plurality of sets of point information consisting of place name information and its position information are stored in the point information storage means 106, and the point information stored in the point information storage means 106 is used to specify a place name in the point information retrieval means 107. It is designed to search and read out the location information.

Further, the point setting means 108 specifies the names of the departure point and destination point of the vehicle to the point information retrieval means 107, and sets each position information read from the point information storage means 106 as the coordinates of each point. ing.

The starting point and destination point set by the point setting means 108 are output to the mark display control means 109 and the place name display control means 110. The output of the place name display control means 110 and the output of the mark display control means 109 are outputted to the display means 105.

The display means 105 is capable of two-dimensional orthogonal coordinate system display and character display.

Based on the positional relationship between the starting point and the destination point set by the point setting means 108, the mark display control means 109 displays a mark indicating the positions of both at a predetermined position on the screen of the display means 105. A mark indicating the current position of the vehicle is displayed on the screen at a specified scale.

Further, the place name display control means 110 displays the names of the departure point and destination point on the display means 105.

By configuring in this way, the display means 10
From the positional relationship between the departure point, destination point, and each mark indicating the current location of the vehicle displayed on the screen of No. 5, the approximate location of the vehicle in motion can be determined.

Next, a specific embodiment of the present invention will be described in detail based on FIG. This FIG. 2 is a schematic configuration diagram showing a specific embodiment of the present invention based on FIG.
2, a keyboard 203, a control circuit 204, a semiconductor memory 205, and a cathode ray tube 206.

The mileage sensor 201 corresponds to the mileage detection means 101 in FIG. 1, and detects the rotation of the wheel using an electromagnetic pickup or reed switch, and generates a signal having a number of pulses proportional to the number of rotations of the wheel. It is output to the control circuit 204. This control circuit 204 corresponds to the current position calculation means 10 in FIG.
3. It includes a mark display control means 109, a point information search means 107, a point setting means 108, and a place name information control means 110.

The direction sensor 202 uses, for example, a flux gate type geomagnetic detector 302 fixed to the vehicle 301 as shown in FIG. The control circuit 204 detects the detected signal and outputs a corresponding signal to the control circuit 204.

The keyboard 203 corresponds to the current position initial setting means 104 in FIG. 1, and as shown in the external view of FIG.
Keys for kana characters such as "ra"..."ro", "wa", "n", etc.
A character key section 40 consisting of a voiced key "''" and a half voiced key "." (the above keys are also called character keys)
1, "Clear", "Complete", "Departure point", "Destination point"
The control key section 402 includes control keys such as "set" and "start". Note that each key is sometimes called a character key "a", a character key "″", a "clear" key, etc. The contents of the keys operated on the keyboard 203 are sent to the control circuit 2.
Loaded on 04.

The semiconductor memory 205 is, for example, a ROM (read
It stores point information consisting of place name information and its position information, corresponds to the point information storage means 106 in FIG. 1, and is read out by the control circuit 204.

For example, point information for Akashi City (representative points are the locations of the city hall) is stored in memories 501a to 505 in FIG.
It is stored in 1g. Memories 501a to 501
In c, the place name information “Akashi” is replaced with the kana character “A”.
It is stored as a code indicating "ka" and "shi".

It is assumed that each memory is composed of 8 bits. The most significant bit of each memory 501a to 501c is to indicate that it is place name information, and the memory 501c that stores the last character of the place name information is "1", and the other memories 5
"0" is assigned to 01a and 501b.

Therefore, the remaining 7 bits in each memory 501a to 501c represent kana characters. With 7 bits, it is possible to express all the clear, voiced, semi-voiced, consonant, and persistent sounds of kana characters.

Memories 501d to 501g store location information of Akashi City, for example, memories 501d and 501
The east longitude is stored in e, and the north latitude is stored in the memories 501f and 501g. Similarly, memory 502a
~502g stores location information of "Kobe".

Furthermore, as position information, as shown in the map of Japan in FIG. 6, coordinate axes X and Y may be set for convenience, and coordinates (X, Y) of relative distances based on these coordinate axes may be stored.

In this case, Japan is expressed within an area of 1700km square, and 1700km is expressed as 2 bytes (16 bits) as described above.
When allocated to 1 bit, it becomes approximately 26 m, which can be a practically sufficient unit in the device of this invention.

For example, there are about 680 cities in Japan, and there are about 300 place names per prefecture, including wards, towns, villages, interchanges, stations, castles, lakes, mountain passes, mountains, etc. There are 13,800 place names in all 46 prefectures excluding Okinawa Prefecture.

If the average number of characters in a place name is 5 characters, and the location information is 4 bytes (X, Y each 2 bytes) as described above, 124,200 bytes are required.

To store this data, the highest capacity 256K-bit ROM on the market to date requires four, but 1M-bit ROM is expected to become commercially available in the future.
In this case, one piece is sufficient, and thus a semiconductor memory 205 that is small, lightweight, and highly reliable can be used.

The cathode ray tube 206 may be of a conventional type and has a rectangular screen 701 as shown in the external view of FIG. Note that the coordinate axes u and v are orthogonal coordinate axes for indicating the coordinates (u, v) on the screen 701, and the screen 701 shows the starting point, destination point,
and each mark of the current location (details will be described later), as well as the names of the departure point and destination point are displayed.

The control circuit 204 is composed of a well-known microcomputer system (not shown), includes various input/output interface circuits (not shown), and based on place name information input by operating the keyboard 203, a semiconductor memory The position information is read out from the sensor 205, an appropriate scale is determined in consideration of the positional relationship between the starting point and the destination point, and a mark indicating each point is displayed, and the place name of each point is also displayed. Signal from and direction sensor 20
2, the current position is calculated based on this, and a mark indicating the current position is displayed on the corresponding coordinates of the screen 701 of the cathode ray tube 206 at a predetermined scale.

Below, the operation of the control circuit 204 will be explained in FIGS.
This will be explained in detail based on the flowchart shown in Figure h. FIG. 8a shows a flowchart of the main routine, which starts with the start of power supply to the control circuit 204, initializes variables etc. in step S101, and then sequentially moves on to point setting preparation processing and step S102. Departure point setting processing in S103,
Destination point setting processing in step S104, step
The subroutines of mark/place name display processing in S105 and current position initialization processing in step S106 are repeatedly executed.

This will be explained using a specific usage example. First, the user operates the "clear" key on the keyboard 203 before setting the starting point and destination point. As a result, this key operation is detected in the flowchart of FIG.
S201, S202), memory for setting each point Pn,
Y, Sn, Xs, Ys, Gn, Xg, Yg (described later) are cleared to zero (step S203).

Next, enter the starting point, for example, if you want to set Akashi City, use the keyboard 203 to enter the starting point.
Operate each key in order as ``Start Point'', ``A'', ``F'', ``Sh'', and ``Set''. As a result, in the flowchart of FIG. 8c showing details of the subroutine of the departure point setting process in step S103 of FIG. 8a, the operation of the "departure point" key is first detected (step
S301, S302), and the place name input/point search processing subroutine of step S303 is executed.

In step S401 of FIG. 8d, which is a detailed flowchart of the subroutine of step S303,
Reads the contents of the operated key and steps
If it is determined in S402 that it is a character key, the memory Pn (n = 1, 2,
) in step S403. 1 letter key
Execute steps S401 to S403 every time the operation is performed,
Therefore, memory P ₁ has "a", P ₂ has "ka",
Each "shi" is stored in P ₃ .

Finally, operate the "Set" key in step S402.
Based on the character strings "a", "ka", and "shi" detected in step S404 and inputted in step S405, the semiconductor memory 205 is searched, and point information (memories 501a to 501a to 501g), and in step S406 its location information (memory 5
01d to 501g), and stores the contents of memories 501d and 501e in memory X and the contents of memories 501f and 501g in memory Y, respectively.

Next, the process returns to step S304 in FIG. 8c, and the input place name information (memory Pn) and searched position information (memories
1, 2, ...), Xs, and Ys, respectively.
This completes the setting of the departure point.

Next, input the destination point, but if you select Kobe City as the destination point, the operation order of each key will be "destination point", "co".
``C'', ``F'', ``'''', and ``Set'', and after operating the ``Destination Point'' key instead of the ``Departure Point'' key in the case of inputting the departure point described above, it is the same as inputting the place name of the departure point. Just operate each key according to the steps. As a result, the destination point setting process subroutine (step S104) shown in FIG. 8a is executed.

Figure 8e shows this subroutine (step S104)
8. Steps S501 and S503 are the steps in the flowchart for the departure point setting process shown in FIG. 8c, respectively.
It is exactly the same as S401 and S403, and the step
In step S502, a judgment is made on the "destination point" key instead of the judgment on the operation of the "starting point" key in step S402, and in step S504, the memory Sn in step S404 is
Instead of transferring information to Xs and Ys, the information is transferred to destination point memories Gn, Xg, and Yg. Therefore, the operation in Figure 8 e is the same as the operation in Figure 8 c. Since it is similar to , a detailed explanation will be omitted.

With the above steps, the setting of the departure point and destination point is completed, so the user operates the "Complete" key. As a result, the subroutine S105 of the mark/place name display process shown in FIG. 8a is executed.

FIG. 8f is a flowchart of the process, and after detecting the operation of the "Complete" key in steps S601 and S602, marks of the departure point and destination point are displayed on the screen of the cathode ray tube 206 of FIG. The horizontal length lx and the vertical length are set virtually in advance in 701.
A scale is determined so as to be displayed on the outer periphery 703 of the rectangular area 702 of ly, and marks of the starting point and destination point are displayed based on this scale.

That is, as set in subroutines S103 and S104 of the departure point setting process and destination point setting process described above, the coordinates of the departure point are (Xs, Ys) and the coordinates of the destination point are (Xg, Yg). First, in step S603, the distance between the starting point and the destination point in the east-west direction |Xs−Xg| and the rectangular area 70
The ratio of the horizontal length lx of 2 to the horizontal length lx = lx / |
Find the ratio ry=ly/|Ys−Yg| with the vertical length ly of is determined as the scale r (steps S605 and S606).

Next, the coordinates of the midpoint between the starting point and the destination point (X ₀ ,
Y ₀ ) is calculated in step _S607 based on the following equation _: In step S608 _, the coordinates are transformed and reduced _by the _scale r to correspond to Calculate based on (Ys−Y ₀ ).

Here, (Us, Vs) are the coordinates of the starting point on the screen 701, and (Ug, Vg) are the coordinates of the destination point, and it is obvious that these coordinates are on the outer periphery 703 of the rectangular area 702.

Next, in step S609, the coordinates (Us,
Vs) (Ug, Vg), as shown in FIG. 9a, a departure point mark 901 and a destination point mark 902.
A display signal is output to the cathode ray tube 206 to display the image.

Finally, in step S610, a signal is output to display the place names of the departure point and destination point based on the memories Sn and Gn.

An example of the display is shown in FIG. 9a, where the top left of the screen 701 shows "Start", below it the place name of the departure point "Akashi", also in the top right corner "Goal", and below that the place name of the destination ""Kobe" is displayed.

Now, when the vehicle 301 shown in Fig. 3 is at the set starting point, the user only has to operate the "start" key immediately, but if the vehicle 301 is at a point a little far away, the coordinates of the starting point (Xs, Ys ), operate the "Start" key. As a result, the current position initial setting process subroutine of step S106 in FIG. 8a is executed.

FIG. 8g shows the flowchart. In steps S701 and S702, the operation of the "start" key is detected, and in step S703, the coordinates of the starting point (Xs,
Ys) to the current position coordinate memories xp and yp used for current position integration calculation.

When the starting point, destination point, and current position are set as described above and the vehicle continues to travel, the unit traveling distance dl (for example, 1 m) is determined based on the pulse signal obtained by the traveling distance sensor 201.
An interrupt signal is input to the microcomputer at each time, and the interrupt processing routine shown in the flowchart of FIG. 8h is executed.

In Fig. 8h, first, in step S801, the direction signals Ha and Hb are input, and the geomagnetic field H shown in Fig. 3→
In step S802, the angle θ formed by the traveling direction 303 of the vehicle 301 is calculated using the following equation θ=tan ⁻¹ (Hb/Ha).

Next, in step S803, the directional components dx and dy for each coordinate axis x and y of the unit traveling distance dl are calculated based on the following equations: dx=dl・sinθ dy=dl・cosθ, and in step S804, the current position up to now is calculated. Add to the integrated values xp and yp of the coordinate components of.

Next, in step S805, the coordinates (up, vp) on the screen 701 are calculated based on the scale r using the following equation up=r(xp-X ₀ ) vp=r(yp-Y ₀ ),
At step S806, the ninth
As shown in FIG. b, a signal is output to display a mark 903 at the current position.

The present invention is configured as described above, and when a starting point and a destination point are specified by place name, the control circuit 204 reads out the positional information of those points from the point information stored in advance, and uses this as the starting point. are set as the coordinates of the destination point, and both points are displayed as marks on the cathode ray tube 206 at an appropriate scale, the place names of these two points are displayed on the cathode ray tube 206, and the current position calculated every moment is displayed as a mark. As a result, it has achieved a navigation function that is extremely suitable for in-vehicle use, as described below.

First, the semiconductor memory 205 stores point information over a wide area by storing point information consisting of place name information and its position information as basic elements, rather than storing map image information as is. becomes possible.

Second, since the starting point and destination point are specified by place name and pre-stored position information is read out and set as the coordinates of both points, accurate positions can be set with a simple operation.

Thirdly, based on the distance and positional relationship between the departure point and the destination point, marks 901 and 902 indicating both are displayed at appropriate positions on the screen 701, and a mark 903 indicating the current position of the vehicle is displayed at a scale determined by the marks 901 and 902. Since it is displayed, the user can be spared from troublesome operations such as setting the position of each mark and setting the scale.

Fourth, by displaying the place names of the departure point and destination point, there is no need to worry about forgetting the place names of each set point.

In this embodiment, as shown in FIG. 2, a semiconductor memory 205 such as a ROM is used as the point information storage means 106 in FIG. 1. However, it is also possible to use a large capacity storage device such as a floppy disk. Needless to say, even more point information can be stored.

Further, instead of inputting with a keyboard, a voice input device may be used.

Furthermore, instead of the cathode ray tube 206, a dot matrix type liquid crystal display device or the like may be used.

〔Effect of the invention〕

As explained above, in the present invention, place names and their geographical coordinates are stored in the storage means, and when the place names of the departure point and destination point are designated by the input means, the control device stores the place names and their geographical coordinates in the storage means. The coordinates of that point are read out, and a mark indicating the departure point and destination point is displayed on the display means at an appropriate scale.A mark indicating the current position of the vehicle is displayed along with the mark, and the coordinates of the departure point and destination point are displayed on the display means. By displaying the names of each location, the vehicle satisfies the in-vehicle requirements of being small, inexpensive, and easy to operate, while also making it easy to distinguish between the departure and destination locations without forgetting the location names, providing a navigation function that is sufficient for practical use. This has the effect of realizing the following.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the in-vehicle navigation device of the present invention, and FIG.
3 is an explanatory diagram of a direction sensor in the navigation device shown in FIG. 2, and FIG. 4 is a block diagram showing a specific embodiment of the present invention based on the in-vehicle navigation device shown in FIG. 5 is a diagram showing a memory map of the semiconductor memory in the in-vehicle navigation device in FIG. 2, and FIG. 6 is a map of Japan for explaining the in-vehicle navigation device in FIG. 2.
7 is an external view of the cathode ray tube of the in-vehicle navigation device shown in FIG. 2, FIGS. FIG. 9A and FIG. 9B are diagrams each showing an example of a display on a cathode ray tube in the in-vehicle navigation device of FIG. 2. 101... Travel distance detection means, 102... Travel direction detection means, 103... Current position calculation means, 1
04...Current position initial setting means, 105...Display means, 106...Point information storage means, 107...
Point information search means, 108...Point setting means, 1
09... Mark display control means, 110... Place name display control means, 201... Mileage sensor, 202
... Orientation sensor, 203 ... Keyboard, 204
... Control circuit, 205 ... Semiconductor memory, 206
...Cathode ray tube. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A traveling distance detecting means for detecting the traveling distance of the vehicle, a traveling direction detecting means for detecting the traveling direction of the vehicle, a traveling distance obtained by the said traveling distance detecting means and a traveling direction obtained by the said traveling direction detecting means. Current position calculation means for calculating the current position of the vehicle from the traveling direction, and for this current position calculation means,
A current position initial setting means for initializing the current position, a display means capable of displaying a plane using a two-dimensional orthogonal coordinate system and character display, and a point information storage storing a plurality of sets of point information consisting of place name information and its position information. a point information retrieval means for searching a corresponding place name from the point information storage means and reading out its position information by specifying a place name; specifying the names of each place of the departure point and destination point of the vehicle to the place name information retrieval means; A point setting means for setting each position information read out by the point information retrieval means as the coordinates of each point; mark display control means for displaying a mark indicating the current position of the vehicle at a predetermined position on the screen of the display means, and displaying on the screen a mark indicating the current position of the vehicle at a scale determined by the mark; An in-vehicle navigation device comprising a place name display control means for displaying a place name on the display means.