JPS6079499A - Running information display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a travel information display device that can display the current position of a vehicle on a map displayed on the screen of a display device.

[Prior art]

Conventional travel information display devices use a travel distance detector such as an electromagnetic pickup to output an electric signal every time the vehicle travels a predetermined distance, and also use a direction detector such as a magnetic sensor to determine the direction of travel of the vehicle. Outputs electrical signals. These electrical signals are then processed and calculated by a control circuit using a microcomputer or the like. In this case, the microcomputer reads the map information stored in memory in advance and displays it on the display, and also displays the vehicle's current position mark, travel trajectory, etc. superimposed on the map displayed on the screen. It is. Therefore, by looking at the display screen, the driver can know the current location of the vehicle he or she is driving, even on roads in unfamiliar areas, by comparing it with a map.

However, in conventional travel information display devices, there is a limit to the storage capacity of the memory, so there is a natural limit to the map information that can be stored. Therefore, if the vehicle deviates from the range of the map stored in the pre-prepared memory, the vehicle's current position mark cannot be superimposed on the displayed map, so the current position of the vehicle cannot be displayed. There was a drawback that the vehicle could not be driven on the intended road because the vehicle was not understood.

[Summary of the invention]

Therefore, it is an object of the present invention that even if the current position of the vehicle deviates from the range of the map stored in the memory prepared in advance,
The present invention provides a driving information display device that allows the current position of a vehicle to be known.

In order to achieve such an object, the present invention includes a mileage detector for detecting the distance traveled by a vehicle, a direction detector for detecting the traveling direction of the vehicle, a map memory storing map information, and a two-dimensional A display device that displays a screen, and a map stored in the map memory mentioned above is displayed on this display device,
The current position of the vehicle is calculated based on the distance traveled by the distance detector and the heading obtained by the direction detector, and a mark indicating the current position of the vehicle is superimposed on the displayed map. and a control circuit that controls the display of the current position in longitude and latitude when the calculated current position of the vehicle deviates from the range of the map stored in the map memory, This will be explained in detail below using examples. , [Embodiment of the Invention] FIG. 1 is a block diagram showing an embodiment of a traveling information display device according to the present invention. In the figure, numeral 1 is a travel distance detector that generates a pulse train signal as the wheels (not shown) of the vehicle rotate, and numeral 2 is a magnetic sensor of the fluxgate type, for example, for direction detection that outputs all analog geomagnetic signals. 3 is a map memory that stores map information such as the map 3a shown in FIG. 3, and 4 is a microcomputer (hereinafter referred to as microcomputer); 5 is the above-mentioned mileage detector. An interface circuit that processes the pulse train signal input from 1 and outputs a pulse to the microcomputer 40 interrupt terminal 4LK every time a unit distance at (for example, 1 m) is traveled to cause the microcomputer 4 to perform interrupt processing; 6 is an azimuth detector; A drive/processing circuit converts the geomagnetic signal output from 2 into a digital geomagnetic signal and outputs it, and a mark 7e (hereinafter referred to as the current position mark) indicating the road 7b and the current position of the vehicle is placed on the T-screen 7a. The points on the screen 7a are aligned with the coordinate axis U as shown in FIG.
A display device capable of displaying a two-dimensional screen such as a CRT displaying the coordinates by T and V; 8 is composed of a switch (not shown), etc. for the user to set the current position mark IC on the display T; It is an operating device.

In addition, the above microcomputer 4. The interface 5 and the drive/processing circuit 6 constitute a control circuit 9. In addition, as shown in FIG. 2, the azimuth detector 2 assumes that the angle between the traveling direction 11 of the vehicle 10 and the direction of the earth's magnetic field H (hereinafter referred to as azimuth angle) is θ, and the direction of the vehicle's traveling direction of the earth's magnetic field H is θ. If it is divided into a parallel component Ha and a perpendicular component Hb, and the magnitude of the horizontal component of the geomagnetic field H is H, then the traveling direction 1 of the vehicle 10 is
A component Ha parallel to 1 and a component Wb perpendicular to it can be expressed as follows.

Ha = kHCO31 ) Ib = klH5iIIO However, k is a constant.

Therefore, the azimuth angle θ can be calculated as follows.

θ-tan-1 (Hb/Ha) Also, in map 3a shown in FIG. 3, a, b and C
is the road, Al~AIO are the bending points when roads a-c are approximated by broken lines, and tl and t2, respectively, are 13 east longitudes.
For example, meridians 9° and 140'', t3 and t4 are latitude lines 36° and 37° north latitude, respectively.Furthermore, FIG. M15 stores the coordinates of corner points A1''A10 of each road a to C, and memory cells M16 to M21 store the meridian t1 indicating the outer circumference of the map 3a.
and t2+latitude lines t3 and t4, respectively. In addition, a flowchart of the main routine of the program of the microcomputer 4 is shown in FIG. 6(,), and a 70-chart of the interrupt processing routine is shown in FIG.
show.

Next, the operation of the driving information display device having the above configuration will be explained with reference to FIG. 6(,) and FIG. 6(b). First, when the control circuit 9 is supplied with power, the microcomputer 4 starts executing the program from the main routine starting point Pl shown in FIG. 6(a)K by a so-called power-on reseller). In step S1, from the map memory 3 to the memory Ml"
”Read M2S and display the display IK map 3a.

First, the memory M1 is read, and it is learned that the memory to be read from now on indicates the corner coordinates of road a. Next, memory M2
. . . M5 are sequentially read out and displayed by connecting each corner point with a straight line on the display 7. When the memory M6 is read out, it is learned that the readout memory indicates the corner coordinates of the road, and the above-mentioned display of the road a is finished. From then on, the memos JM7 to MIO are sequentially read out, and the display is the same as the above-mentioned display of the road a. Road signs will be displayed. The same applies to road C. Also, read memory cells M16 to M21, and map 3 Todoroki is 13 east longitude.
We know that it is bounded by meridians i and latitudes of 9° and 140°, 36° north latitude, and 37° north latitude. This step S1
When the execution is completed, the display on the display I can be shown as shown in FIG. 7(-). In step S2, the current position mark 7C is displayed approximately in the middle of the screen 7a of the display 1. Step S3
Now let's set the current position mark IC. That is, during execution of step S3, the user operates the operating device 8 to freely move the current position mark IC on the screen 7a of the display 7 to match the actual current position of the vehicle 10. The coordinates of the current position at this time are ``O+ 3'0
The coordinates on the % display I are uol"0. This step S3 is used to correct the calculation error of the current position that occurs as the vehicle 10 travels, so it is repeatedly executed. In this way, the map Display, current position mark 7c
After completing the settings, when the vehicle 10 is driven, an interrupt command is input to the microcomputer 4 every unit pressure 1IIIdt based on the pulse train signal output from the mileage detector 1. As a result, the interrupt processing routine shown in FIG. 5(b) is executed. In FIG. 5(b), P2 indicates the starting point of this interrupt processing routine.

First, in step S4, each component Ha and Hb of the geomagnetic field H obtained by the azimuth detector 2 are input as digital quantities. Next, in step S5, the azimuth angle θ can be calculated based on the components Ha and Hb input in step S4 as follows: θ=tan-1(Hb/Ha). Step S6
, the azimuth angle 0 is considered to be constant while the vehicle 10 travels a unit distance di, and the unit distance di.

The components dx and dy of the X-axis and y-axis are calculated. That is,
As can be easily seen from FIG. 2, dx = dl @sinθ d7=dt"cO5θ. In step S7, the coordinates X of the current position of the vehicle 10 are
+7 is x=x1-)dx)""7m+d7 Here, X1+71: Accumulate according to the coordinate component value at the time of the previous interrupt processing. In step S8, the amount of movement of the display 7 on the screen 7a corresponding to the amount that the ball 10 has actually moved is calculated. Assuming that the scale of the map displayed on the display T is S, the amounts of movement du and dv on both surfaces 7a are du = 5-dx dv = s.dy. In step S9, the coordinates U of the current position mark 7c on the screen 7a of the display device 7, ■ are u = u 1
+ d u v = v 1 + d v Here, "1lvl: Integration is performed using the coordinate component value at the time of the previous interrupt processing. In step SIO, the vehicle 10
It is determined whether it is within the range of a. For example, the coordinates x and y of the current position of the vehicle 10 are xa (z (xb and ya < y < yb, where xa: X-axis intercept of 139° east longitude xb 2 east longitude 14
If the X-axis intercept ya at 0°: the y-axis intercept yb at 36° north latitude and the y-axis intercept yb at 37° north latitude are satisfied, it is determined to be within the range of the map 3a, and otherwise it is determined that it has deviated from this range. Step Sll is executed after determining that the vehicle 10 is within the range of the map 33 in the above-mentioned step 810, displays the current position mark 7c on the coordinates u and v calculated in step S9, and displays the current position mark 7c from the return point P3. Return to the main routine shown in Figure 6 (,). Step 812 is executed when it is determined in step 810 that the vehicle 10 has deviated from the range of the map 33, and the coordinate X of the vehicle 10 is determined.

y, the current position of the vehicle 10 is converted into longitude and latitude, and this is displayed in step si3, as shown in FIG. 6(a).
Return to the main routine shown. FIG. 7(b) is a display example in this case. In this way, even when the vehicle 10 deviates from the range of the map 33 stored in the map memory 3, the current position is displayed based on longitude and latitude, so you can refer to a normal road map etc. Yes, you can know your current location.

By providing steps 814 and 81 shown in FIG. 8 between steps sto and 5ll (7) in FIG. 6(b), after the vehicle 1o deviates from the range of the map 3a,
When the user returns to the range of the map 3a again, this is determined in step 814, and the map is redisplayed in step sl, so that the current position mark 1c can be displayed.

〔Effect of the invention〕

As explained in detail above, according to the driving information display device according to the present invention, when the calculated current position of the vehicle deviates from the range of the map stored in the map memory, the current position of the vehicle is This has the effect of making it possible to reliably drive on the desired road even in unfamiliar areas.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the travel information display device according to the present invention, FIG. 2 is a diagram for explaining the operation of the direction detector shown in FIG. 1, and FIG. 3 is a map of FIG. 1. FIG. 4 is a diagram showing the map stored in the memory; FIG. 4 is a diagram showing the memory map of the map memory in FIG. 1; FIG. 5 is a perspective view of the display device showing the coordinate axes in the display device in FIG. 1; FIG. (a) and FIG. 6(b) are flowcharts showing the main routine program and interrupt processing routine program of the microcomputer in FIG. 1, respectively, and FIG. 7(-) and FIG. 7(b) are the display FIG. 8 is a flowchart showing another program of the interrupt processing routine of FIG. 1. 1... Travel distance detector, 2... Direction detector, 3
...Map memory, 3a...Map, 4...Microcomputer, 5...Interface circuit,
6...Drive/processing circuit, 7...Display device, 7a...
...Screen, 7b...Road, 7c...Mark indicating current position, 8...Control device, 9...Control circuit, 1o...Vehicle, 11...・Direction of travel. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa

Claims (1)

[Claims] A mileage detector that detects the distance traveled by the vehicle, a direction detector that detects the traveling direction of the vehicle, a map memory that stores map information, a display that displays a two-dimensional screen, and the map memory. The stored map is displayed on this display, and the current position of the vehicle is calculated based on the mileage obtained by the mileage detector and the traveling direction obtained by the direction detector. A driving information display device comprising a control circuit that controls display of a mark indicating the current position of a vehicle overlaid on a displayed map, wherein the control circuit controls the display of the vehicle so that the calculated current position of the vehicle is stored in the map memory. 1. A driving information display device comprising means for displaying and controlling the current location in longitude and latitude when the vehicle deviates from the range of the current map.