JPH0116368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an in-vehicle navigator that displays the current location of a vehicle on a road map.

Conventionally, this type of device was disclosed in Japanese Patent Application Laid-open No. 55-159299.
There is a "vehicle traveling position display device" in the publication, which is equipped with a distance sensor that generates a distance signal for each unit traveling distance of the vehicle and a direction sensor that detects the traveling direction of the vehicle. Displayed on the road map.

However, due to errors contained in the distance sensor itself or errors in the cable drive gear ratio used for this distance sensor, errors may occur in the unit distance traveled by the distance signal from the distance sensor, and this may cause an error in the current position. There is a problem that the road map cannot be displayed accurately on the road map.

The present invention has been made in view of the above problem, and has a function of storing a preset distance correction value, and corrects the unit traveling distance based on the distance signal from the distance detection means using the stored distance correction value. By having means for calculating the current position using the corrected unit mileage, it is possible to correct the unit mileage based on the distance signal from the distance detection means and accurately display the current position on the road map. The present invention relates to an in-vehicle navigator.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall configuration diagram showing one embodiment. In Fig. 1, reference numeral 1 denotes a direction detection device as direction detection means, which includes a direction sensor that detects the X and Y components of the earth's magnetism according to the direction in which the vehicle is traveling, and converts the signal from this direction sensor into a digital signal. It is equipped with an A/D converter and generates digital signals of X and Y components depending on the traveling direction of the vehicle. Reference numeral 2 denotes a distance sensor as a distance detecting means, which generates a distance pulse every unit traveling distance of the vehicle (for example, about 39.2 cm). Reference numeral 3 denotes a reading device which searches for and reads the map data of a specific district using a set of cassette tapes 3a which store map data of a plurality of districts (including absolute coordinate data of the upper right point of each map). It is something.

4 is a microcomputer that executes software digital arithmetic processing according to a predetermined control program, and includes a CPU 4a, a ROM 4b, and a RAM.
4c and an I/O circuit section 4d constitute a calculation means, and it receives power from the on-board battery and receives 5V.
It is activated by receiving a stabilized voltage from a stabilized power supply circuit (not shown) that generates a stabilized voltage of It receives distance pulses, read signals from the reader 3, etc., performs arithmetic processing, and generates display signals for displaying a map of a specific area, travel route information, etc. Note that the RAM 4c is constantly backed up with power from the on-board battery. In addition, ROM4
A predetermined distance correction coefficient is stored in b.
The input distance correction coefficient is stored in the RAM 4c.

5 is a cathode ray tube (CRT) controller,
In response to a display signal from the microcomputer 4, map data, driving route information, and character data of a specific area are individually stored, and the stored map data, driving route information, or character data is displayed on a CRT. It generates video signals and synchronization signals for 6 is
This is a CRT display device that displays a map, driving route, or characters of a specific area using the video signal and synchronization signal from the CRT controller 5. Reference numeral 7 denotes a touch panel section, which is attached to the display surface of the CRT display device 6 and generates a serial signal in response to a touch operation on a specific touch area among the 12 divided touch areas provided on this touch panel. be. 8 is a digital switch unit for inputting a distance correction coefficient by external operation, and includes three digital switches (input in decimal notation) and a set switch that generates input timing (interrupt signal to microcomputer 4). This is for inputting into the microcomputer 4 the distance correction coefficients (three digit numbers including two digits below the decimal point) obtained by the three digital switches.

Next, the CRT controller 5 shown in FIG.
The detailed electrical wiring diagram will be explained. 11 is
Oscillation circuit that generates a 12.096MHz oscillation signal, 12
divides the oscillation signal from oscillation circuit 11 to 6.048M
A dot counter 13 generates a dot timing lock of Hz and a character timing lock of 756KHz.A horizontal and vertical synchronizing signal, a display timing signal, A display controller 14 generates a refresh memory address signal and a raster address signal, and a display controller 14 generates a hold signal for holding the microcomputer 4 during the display period based on the horizontal and vertical synchronization signals from the display controller 13. This is a hold signal generation circuit that is generated at the HOLD) terminal. 15 is a multiplexer which switches the address signal from the microcomputer 4, the refresh memory address signal from the display controller 13, and the raster address signal in response to a hold acknowledge (HOLDA) signal from the microcomputer 4; 16, 17, and 18 A bus driver 19 has a tri-state that switches the direction of data between the microcomputer 4 and the display memory, and a bus driver 19 stores display data such as ASCII codes from the microcomputer 4 and receives a refresh memory address signal from the display controller 13. A character memory 20 receives the data and outputs the contents as an address, and a character generator 20 outputs a display pattern based on a display address from the character memory 19 and a raster address signal from the display controller 13. 21 is a first graphic memory that stores map data from the microcomputer 4; 22 is a second graphic memory that stores travel route information (travel trajectory data, current position data) from the microcomputer 4; 23; 24 and 25 are parallel to serial (P to S) converters that convert parallel signals from the character generator 20 and the first and second graphic memories 21 and 22 into serial data using the dot timing clock from the dot counter 12.
A converter 26 switches reception of signals from the P→S converter 23 and P→S converters 24 and 25 in order to select between graphic and character screens in response to a screen switching signal from the microcomputer 4. A video controller 27 generates a video signal using a display timing signal, and 27 is an exclusive OR circuit that generates a synchronization signal using horizontal and vertical synchronization signals from the display controller 13. Note that the character memory 19, the first
The second graphic memories 21 and 22 are constantly backed up with power from an on-vehicle battery.

That is, this CRT controller 5 stores character data in the character memory 19 based on the data sent from the microcomputer 4.
Then, the map data is stored in the first graphic memory 21.
The display data of the travel trajectory and current position is constantly stored in the second graphic memory 22, and the graphic screen (displaying the travel trajectory and current location on the map) and characters are displayed by a screen switching signal from the microcomputer 4. The CRT display device 6 generates a video signal and a synchronization signal for selecting a screen (displaying designated characters, etc. to designate a district) and displaying a screen corresponding to the selection on the CRT.

The touch panel section 7 has touch areas divided into 12 sections, numbered 31 to 42, as shown in FIG. When a specific touch area is pressed, the touch area is detected by the contact of the transparent conductive power source of the matrix due to the deflection of the glass, and a serial signal corresponding to the touch area detected by a touch signal generation circuit (not shown) is generated. (consisting of a start signal and a touch information signal). Note that this touch signal generation circuit generates the touch information at that time in the form of a serial signal every 40 msec.

Furthermore, Fig. 4 shows a data area corresponding to one district on the cassette tape 3a, and A is a header section that stores the absolute coordinates (coordinates with respect to the North Pole) of the upper right point of the map of that region. , B is a map data storage section that stores map data of the area, and X is a blank section. Therefore, by reading portions A and B with the reading device 3, map data and absolute coordinate data of a specific area can be provided to the microcomputer 4.

The operation of the above configuration will be explained with reference to the display explanatory diagram in FIG. 5 and the calculation flowcharts shown in FIGS. 6 to 10. FIG. 6 is a calculation flowchart showing the overall calculation processing of the main routine of the microcomputer 4, FIG. 7 is a calculation flowchart showing the calculation processing of the interrupt calculation routine based on the distance pulse from the distance sensor 2, and FIG. FIG. 9 is a calculation flowchart showing detailed calculation processing of the mode calculation routine in FIG. 6, FIG. 9 is a calculation flowchart showing detailed calculation processing of the current position calculation routine in FIG. 6, and FIG. 2 is a calculation flowchart showing interrupt calculation processing based on the interrupt signal of FIG.

Now, in a vehicle equipped with components 1 to 7 shown in FIG. 1, when a key switch is turned on at the start of operation, each part of the electrical system is activated by receiving power from the vehicle battery. Then, the microcomputer 4 receives the stabilized voltage of 5V from the stabilized power supply circuit and enters the operating state, starts its calculation processing at the start step 100 in FIG. 6, and proceeds to the initial setting routine 200. The registers and counters in the microcomputer 4,
Sets latches, etc. to the initial state necessary to start arithmetic processing. After this initial setting, the mode calculation routine 300 and the current position calculation routine 400 are repeatedly executed at a cycle of approximately several tens of milliseconds.

That is, in this mode calculation routine 300,
Select either map mode or character mode and select the content according to that mode.
A CRT display is performed, and when in map mode, a cursor indicating the current position can be moved, and when in character mode, calculation processing is executed to enable map designation of a specific area, and the process proceeds to current position calculation routine 400.
In this current position calculation routine 400, the current position data and traveling trajectory data in the second graphic memory 22 of the CRT controller 5 are
A calculation process is executed to change the content based on a travel change of ±50m for each component, and the mode calculation routine 300 is executed.
Return to Thereafter, the main routine arithmetic processing from the mode arithmetic routine 300 to the current position arithmetic routine 400 is repeatedly executed at a cycle of approximately several tens of milliseconds.

Then, when an interrupt signal is applied to the interrupt (INT) 1 terminal of the microcomputer 4 by the set switch set in the digital switch unit 8 for the repeated operation of this main routine, the microcomputer 4 starts the operation of the main routine. The process is temporarily interrupted and the interrupt calculation process shown in FIG. 10 is executed. That is, the arithmetic processing is started from the first interrupt start step 601, and the process proceeds to a distance correction coefficient input storage step 602 where the distance correction coefficient signal from the digital switch section 8 is inputted.
The data is stored as data _k2 in the distance correction coefficient holding address of the RAM 4c (changed from the previously stored data _k2 ), and the process advances to return step 603 to return to the previously interrupted main routine.

Further, each time a distance pulse from the distance sensor 2 is applied to the INT2 terminal of the microcomputer 4 for the repeated calculation of the main routine, the microcomputer 4 temporarily suspends the calculation processing of the main routine and returns to FIG. Executes the interrupt calculation process shown. That is, the arithmetic processing is started from the interrupt start step 501, and the process proceeds to the integration step 502, where the distance correction coefficient data k (digital switch section 8
When the distance correction coefficient is not inputted by the digital switch 8, the data k ₁ set in advance in the ROM 4b is stored, and after the distance correction coefficient is inputted by the digital switch 8, it is stored in the distance correction coefficient holding address of the RAM 4c. Using the data k ₂ ), c×k (c is approximately 39.2
unit distance data expressed in cm (equivalent to cm)
The distance data D stored in step 4c is integrated to update the distance data D, and the process proceeds to distance determination step 503, where it is determined whether or not the distance data D has reached 6.25 m. At this time, if the distance data D is not 6.25m, the judgment will be NO and the return step will not be executed.
Proceed to 510, but when the distance data D reaches 6.25m, the judgment becomes YES and the direction signal input step is started.
Proceed to 504. Then, this direction signal input step
At 504, the digital X from the direction detection device 1,
Input the Y component signals Xa, Ya (positive directions for east and north, negative directions for west and south), proceed to step 505 to calculate average direction, and calculate the previous direction data Xo, Yo (direction data before traveling 6.25 m) and this direction data Xa, Ya
The average azimuth data X, Y is obtained by calculating the distance component Dx in the
6.25X/√ ² + ² The distance component Dy in the Y direction is 6.25Y/
Obtained as √ ² + ² (X/√ ² + ² is cosθ for the counterclockwise angle θ with the east direction as the reference, Y/√
(X ² + Y ² corresponds to sin θ) Proceed to storage step 507 and save the current direction data Xa, Ya as Xo,
Memorize as Yo and Distance Data Reset Step
The program proceeds to step 508 to reset the distance data D to 0, proceeds to a distance flag set step 509 to set the distance flag, and proceeds to return step 510 to return to the previously interrupted main routine. That is, in this interrupt calculation routine, the distance data D is cumulatively updated every time a unit distance is traveled, and the distance data D is
When the distance reaches 6.25 m, the distance components Dx and Dy in the X and Y directions reaching this 6.25 m are calculated, and arithmetic processing is executed to set a distance flag. Note that the interrupt arithmetic processing shown in FIG. 7 has a lower interrupt priority than the interrupt arithmetic processing shown in FIG.

Next, detailed calculation processing of the mode calculation routine 300 in the main routine will be explained. In this mode calculation routine 300, the calculation process starts from the touch data input step 301 in FIG.
Input touch data from touch panel section 7
Store in RAM4c. Then, the process advances to map mode determination step 302, where it is determined whether the contents of the mode area in RAM 4c are map mode, and when it is map mode, the determination becomes YES, and the process advances to mode change determination step 303, where the content of the mode area in RAM 4c is YES.
It is determined whether the touch data stored in 4c is data indicating a mode change (data when touch area 34 in FIG. 3 is pressed).
At this time, if the touch data is data indicating a mode change, the determination becomes YES, and the process proceeds to character mode setting step 304, sets the contents of the mode area to character mode, and proceeds to character switching signal output step 305. Then, a character switching signal for displaying a character screen on the CRT display device 6 is generated to the video controller 26 in the CRT controller 5, and one calculation process of this mode calculation routine 300 is completed.

On the other hand, when the touch data is not data indicating a mode change, that is, data when a touch area other than 34 in Fig. 3 is pressed, or data when no touch area is pressed (for example, data FF). Sometimes, the determination in the mode change determination step 303 becomes NO, and the process proceeds to the cursor movement determination step 306. In this cursor movement determination step 306, the touch data is 32,
Determine whether the data is the data (cursor movement data) when any of the touch areas 33, 35, 38, 40, or 41 is pressed, and if the touch data is not the cursor movement data, the judgment is NO. One calculation process of this mode calculation routine 300 is completed, but if the touch data is cursor movement data, the determination becomes YES and the process proceeds to cursor movement calculation step 307. In this cursor movement calculation step 307, in accordance with the touch data, the cursor at the current position displayed on the CRT display device 6 is moved a predetermined distance northward, indicating that this touch data corresponds to the press of touch area 32 or 33. The content of the second graphic memory 22 in the CRT controller 5 is changed so that the touch data is 35, and the cursor is moved westward when the touch data is 40 or 41. The contents of the second graphic memory 22 are stored so that if the data corresponds to the press of the touch area, the cursor is moved southward, and if the data corresponds to the press of the touch area 38, the cursor is moved eastward by a predetermined distance. The arithmetic processing to be changed is executed, and one arithmetic processing of this mode arithmetic routine 300 is completed.

On the other hand, if the determination in the map mode determination step 302 is NO, the process advances to a mode change determination step 308.
It is determined whether or not the mode is to be changed using the same calculation process as in the mode change determination step 303. At this time,
When the mode is changed and the determination is YES, the process proceeds to map mode setting step 309 to set the contents of the mode area in RAM 4c to map mode, and proceeds to data conversion step 310 to change the CRT controller 5.
The travel route data in the second graphic memory 22 is converted. In this case, the reading device 3 is first controlled to search for a designated area using its map number, and the absolute coordinates (fourth
A coordinate conversion value is calculated using the absolute coordinate data of the previous map (stored in the header section A shown in the figure) and the second graphic memory 22 according to this calculated value.
Converts the travel trajectory and current position data in a sliding manner. Then, the process proceeds to map data reading and outputting step 311, where map data from the cassette tape 3a is inputted via the reading device 3, and the map data is output to the first graphics memory 21, and the process proceeds to map switching signal outputting step 312. in
A map switching signal for displaying a map graphic screen on the CRT display device 6 is generated to the video controller 26, and one calculation process of this mode calculation routine 300 is completed. That is, when switching from the character screen to the graphic screen of a map different from the previous one, the above calculation process is executed, the current map data is stored in the first graphic memory 21, and the current location corresponding to this map is The contents in the second graphics memory 22 are converted to modify the travel trajectory and the cursor indicating the current location. As a result, even if the map displayed on the CRT display device 6 is changed, the travel trajectory and current location can be displayed in the area corresponding to the map.

On the other hand, if the determination in the mode change determination step 308 is NO, the process advances to a character calculation step 313.
When the character calculation step 313 is reached, the character mode has been set and a character switching signal has been issued to the video controller 26, so the CRT display device 6 can display the character as shown in FIG. The screen is being imaged. The number 02-4 shown in the center of this character screen
-68 is a number that designates a region, region, or district, and each number is updated by adding 1 by increment switch 51, subtracting 1 by 1 by decrement switch 52, and is set and reset by set switch 53. The character calculation step is reset by switch 54.
Arithmetic processing is performed at 313. Furthermore, this region, region,
District numerical data, i.e. map number, is stored in RAM
4c. Further, the switches 51, 52, 53, and 54 mentioned above correspond to the touch areas 39, 40, 41, and 42 in FIG. 3, respectively.

That is, in the mode calculation routine 300 shown in FIG. 8, the following operations are performed according to the touch data from the touch panel section 7 and the contents of the mode area in the RAM 4c.

If there is an instruction to move the cursor when the map mode is in the map mode and the mode is not changed, arithmetic processing for moving the cursor is executed, and if there is no instruction to move the cursor, the map display is continued as it is.

If there is an instruction to change the mode while in the map mode, the map mode is changed to the character mode and the character screen is displayed on the CRT display device 6.

When the character mode is in effect and the mode is not changed, map changes can be accepted on the character screen as shown in FIG.

When a mode change instruction is given while in the character mode, the character mode is changed to the map mode, a graphic screen of the map is displayed on the CRT display device 6, and at the same time, the travel trajectory and current position are corrected and displayed.

Next, detailed calculation processing of the current position calculation routine 400 in the main routine will be explained. In this current position calculation routine 400, the calculation process starts from the distance flag determination step 401 in FIG.
In the interrupt calculation process shown in FIG. 7, it is determined whether the distance flag is set. At this time, if the distance flag is not set, the determination becomes NO and one calculation process of this current position calculation routine 400 is completed, but if the distance flag is set, the determination becomes YES and X Distance correction step 402
Proceed to. Then, in this X distance correction step 402, the X distance data Dx obtained by the interrupt calculation process is
Correction calculation using distance component Dx (DX=DX+Dx)
Then, in the Y distance correction step 403, the Y distance data is
Correcting DY is similarly calculated (DY=DY+Dy), and the process proceeds to the first X distance determination step 404, where it is determined whether the X distance data DX has reached a value of 50 m or more. At this time, if the X distance data DX is a value of 50 m or more, the determination becomes YES, and the process proceeds to an X distance subtraction step 405 where the value of 50 m is subtracted from the X distance data DX, and the process proceeds to a display movement step 406 to 2
The current position data in the graphic memory 22 of
The vehicle is moved in the forward direction (eastward) by 50 meters, and the traveling trajectory data is also made to follow this movement.

If the determination in the first X distance determination step 404 is NO, the process proceeds to a second X distance determination step 407, in which it is determined whether the X distance data DX has reached a value of -50 m or less. At this time, the X distance data
If DX is a value of -50m or less, the determination becomes YES, and the process proceeds to X distance addition step 408, where the value of 50m is added to the X distance data DX, and the display movement step is performed.
Proceeding to step 409, the current position data in the second graphic memory 22 is moved in the negative direction (westward) by 50 m, and the traveling locus data is also caused to follow this movement.

Then, when the judgment in the second X distance judgment step 407 is NO, or in the display movement step 406,
After step 409, the routine advances to Y component display movement processing routine 410, where the same determination and calculation processes as in steps 404 to 409 are executed on the Y distance data DY calculated in Y distance correction step 403. (Y distance data
When DY reaches a value of 50 m or more in either the positive or negative direction, the current position data and traveling trajectory data in the second graphic memory 22 are moved by 50 m in the corresponding direction. ) The process then proceeds to the next distance flag reset step 411 to reset the distance flag.

That is, in the current position calculation routine 400 shown in FIG. 9, the current position data and travel trajectory data in the second graphic memory 22 are converted regardless of the screen displayed on the CRT display device 6.

Therefore, the current position data and traveling trajectory data in the second graphic memory 22 are calculated by repeating the main routine calculations by the mode calculation routine 300 and the current position calculation routine 400 and by the interrupt calculation shown in FIG. At the same time, the screen of the CRT display device 6 is selected according to the specified mode, and if it is in the map mode, the map graphic screen (including the display of the current position and driving trajectory) is displayed, and the character In the mode, a character screen for specifying a map shown in FIG. 5 is displayed.

In the above embodiment, the digital switch unit 8 is used as a means for inputting the distance correction coefficient, but it is also possible to input the coefficient from a touch panel. That is, the mode calculation routine
300 has a new correction coefficient input mode,
The switches 61 to 64 which generate the display shown in Fig. 11 (the functions are the same as those shown in Fig. 5 51 to 54)
Input the required distance correction coefficient by appropriately operating . Furthermore, instead of the digital switch unit 8, a keyboard equipped with numeric keys may be used to input the distance correction coefficient. Furthermore, although the cassette tape 3a is shown as a device for storing map data, it is also possible to use a replaceable cassette tape 3a.
ROM may also be used.

As described above, in the present invention, a preset distance correction value is stored, the unit travel distance based on the distance signal from the distance detection means is corrected by the stored distance correction value, and the corrected unit travel distance is The current position of the vehicle is calculated based on the distance and the direction of travel of the vehicle detected by the direction detection means, and this calculated current position is displayed on the display screen of the road map, so the distance from the distance detection means is calculated. Correcting the signal has the excellent effect of eliminating various errors related to distance detection and accurately displaying the current position on the road map. Moreover, the second distance correction coefficient data is stored in advance in the ROM, and the first distance correction coefficient data set and input to the input means is stored in RAM in a non-volatile manner, so that the setting input to the input means is performed. Until this is done, the second distance correction coefficient data is used, and after the setting is input to the input means, the first distance correction coefficient data is used to correct the distance. Even before the settings are entered by
It is possible to perform distance correction using the distance correction coefficient data of , and therefore, even in this case, there is an excellent effect that accurate current position display can be performed.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
Figure 2 is a detailed electrical wiring diagram of the CRT controller in Figure 1, Figure 3 is an explanatory diagram showing the touch area of the touch panel, Figure 4 is an explanatory diagram showing the data area of the cassette tape, and Figure 5 is the CRT display. A display explanatory diagram showing the display state of the device, Fig. 6 is a calculation flowchart showing the overall calculation processing of the main routine of the microcomputer, and Fig. 7 shows the calculation processing of the interrupt calculation routine based on the distance pulse from the distance sensor. Calculation flowchart, Figure 8 is a calculation flowchart showing detailed calculation processing of the mode calculation routine in Figure 6;
The figure is a calculation flowchart showing the detailed calculation processing of the current position calculation routine in Fig. 6, Fig. 10 is a calculation flowchart showing the interrupt calculation processing based on the interrupt signal from the digital switch section 8, and Fig. 11 is a calculation flowchart showing the detailed calculation processing of the current position calculation routine in Fig. 6. It is a display explanatory diagram for explaining an example. 1... Direction detection device as direction detection means, 2
...Distance sensor as distance detection means, 4.. Microcomputer as calculation means, 6.. CRT display device as display means, 8.. Digital switch unit.

Claims (1)

[Scope of Claims] 1. Distance detection means that generates a distance signal for each unit traveling distance of the vehicle, azimuth detection means that detects the traveling direction of the vehicle, and based on signals from the distance detection means and the azimuth detection means. In an in-vehicle navigator that is equipped with a calculation means for calculating the current position of the vehicle while the vehicle is traveling, and a display means for displaying the current position on a display surface of a road map based on a signal from the calculation means, the navigation device responds to an input operation. an input means for outputting first distance correction coefficient data from the input means; a RAM for storing updateably non-volatile first distance correction coefficient data from the input means; and a RAM for storing predetermined second distance correction coefficient data. the ROM, and the ROM while the first distance correction coefficient data is not stored in the RAM by the input means.
The unit mileage based on the distance signal from the distance detecting means is corrected using the second distance correction coefficient data stored in the RAM, and after the first distance correction coefficient data is stored in the RAM by the input means,
a correction means for correcting a unit traveling distance based on a distance signal from the distance detection means using first distance correction coefficient data stored in a RAM;