JPH0821158B2 - Navigation system - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a navigation system installed in an automobile, and in particular, the current position is overlaid on the map information displayed on the display unit so that the driver can The present invention relates to a navigation system capable of easily traveling from a travel start point to a travel destination phrase.

[Background of the Invention]

In the past, when driving long distances, I often got lost in unfamiliar land. In order to make up for such a defect, an in-vehicle navigation system has been proposed.For example, in the navigation system disclosed in Japanese Patent Laid-Open No. 57-201808, the road is displayed on the screen of the in-vehicle CRT. The current position of the car is displayed on the map and overlaid on it, making it easy to know where the car is currently traveling. In this conventional technique, in order to display the current position in progress on the map, first, the running start point is designated and displayed on the displayed map, and after the vehicle has run, the vehicle speed is changed according to the vehicle speed. Data obtained from a distance sensor that generates a pulse and a direction sensor is calculated to obtain a position on the map.

By the way, in such a navigation system, a road map having different scales is displayed depending on the place where the automobile is traveling. This is because a more detailed road map is needed when driving in an urban area where roads are complicated and intricate compared to when driving in a place where roads are not complicated such as in the suburbs.

However, when road maps with different scales are displayed in this way, it is difficult to grasp the sense of distance with respect to each of the displayed road maps. For example, even if a road map of a certain scale is displayed and the distance from one crossing point to the next crossing point from a meter or clock is measured and the clock is sensed, the displayed road map If the map changes to a road map with a different scale, the sense of distance for this will be lost for a while.

[Object of the Invention]

An object of the present invention is to provide a navigation system which solves the above-mentioned problems of the prior art and enables the user to easily and quickly grasp the sense of distance of the displayed road map even if the scale is different. .

[Outline of Invention]

In order to achieve this object, the present invention displays an actual distance per unit length on a display screen obtained by a scale factor of a road map to be displayed at a predetermined position. There is a feature in the point.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the navigation system according to the present invention, in which 1 is a microcomputer unit, 2 and 3 are direction sensors, 4 is a vehicle speed pulse sensor, 5
Is an operation switch unit, 6 is an external storage device, 7 is a display unit, 8
Is an amplifier and 9 is a speaker.

In the figure, the azimuth sensor 2 is a geomagnetic sensor that can obtain an absolute traveling direction, and the azimuth sensor 3 can obtain a relative azimuth. For example, a sensor such as an optical gyro. The geomagnetic sensor detects the absolute traveling direction, but since the geomagnetism is easily affected by disturbances such as buildings, high-voltage lines, railroad crossings, slopes, and iron bridges, errors in the traveling direction are likely to occur. For this reason, an optical gyro or the like, which has a high measurement accuracy although it is a relative orientation, is used for correction. From the direction sensor 2, the absolute direction of travel is X, which is an analog amount on the display unit 7.
It is output as the Y component. The vehicle speed pulse generator 4 generates a pulse having a driving frequency according to the vehicle speed. The pulses from the vehicle body pulse generator 4 are accumulated in the microcomputer unit 1 to calculate the mileage of the vehicle, and the current position of the vehicle is obtained from this mileage data and the traveling direction data from the direction sensors 2 and 3. The current position is displayed on the road map displayed on the display unit 7 based on the current position data.

The operation switch unit 5 is operated by a driver or the like, and is used for designating a road map to be displayed, setting a travel start point on the displayed road map, a travel destination point, and the like. The operation switch section 5 has switches 11 to 19 as shown in FIG. The switches 15 to 18 are operated for designating a road map to be displayed and designating a travel start point and a travel destination point. The switch 11 is a set switch for displaying these on the display unit 7 (FIG. 1) after the road map is specified and the travel start point is specified by operating the switches 15-18. The switch 12 is the switches 15-18. After the travel destination point is specified by the operation, the set switch is displayed on the display unit 7. The switches 13, 14, 19 are the display unit 7.
Used to correct the current position displayed on the screen. The external storage device 6 is, for example, a large-capacity memory such as a tape recorder, and stores each road map information and
Various driving conditions such as the scale of the road map and the intersections and structures that serve as a guide for driving are stored, and these pieces of information are read out to the microcomputer unit 1. The display unit 7 is a television receiver having a color cathode ray tube capable of receiving television programs, a liquid crystal display, or the like, and is a road map read from the external storage device 6 under the control of the microcomputer 1. And the current location, destination point, etc. are displayed. In addition, when the current location approaches an intersection, a structure, etc. that is a standard, the microcomputer unit 1
Generates and outputs a voice signal representing an intersection, a structure or the like from information on a predetermined traveling condition read from an external storage device. This audio signal is amplified by the amplifier 8 and then supplied to the speaker 9 to inform the driver that the object which is the reference is approached.

FIG. 3 is a block diagram showing a specific example of the microcomputer section 1 of FIG. In the figure, reference numeral 31 is an MPU (microprocessor unit) which is the core of the microcomputer unit 1 and controls the operation of the microcomputer unit 1. 32 is a RAM (random access memory) used for temporary data storage in the process of the MPU 31 performing calculation and control operations. The power supply of this RAM is a system different from the system power supply, and the system power supply is Even in the off state, power is always supplied from the battery mounted on the vehicle, and the stored contents are guaranteed. 33 is MPU 31
This is a ROM (read-on memory) that stores programs for various control operations and arithmetic processing operations. Reference numeral 34 is an input / output control circuit for inputting various data input from the interfaces 36 to 39 to the MPU 31. Interfaces 36 to 39 perform level conversion and waveform shaping of input / output data signals. The interface 36 has a bearing sensor 2 (Fig. 1).
A direction sensor 3 (FIG. 1) is connected to the interface 37, a vehicle speed pulse sensor 4 (FIG. 1) is connected to the interface 38, and an operation switch unit 5 is connected to the interface 39. When the external storage device 6 is a small magnetic tape device, 35 is for controlling the small magnetic tape device for controlling input / output of control signals and data (road map information, various running conditions, etc.) between the device and the MPU 31. It is a circuit (hereinafter abbreviated as CMTC). The interface 40 performs signal processing for ensuring transmission and reception of information signals between the CMTC 35 and the small magnetic tape device. Reference numeral 41 is a display unit control circuit (hereinafter, abbreviated as CRTC) which is the core of the circuit unit for sending various display data to the display unit 7 (Fig. 1), and the display data contents are all controlled by this CRTC41. To be done. Reference numeral 42 is a timing signal generator that generates a reference clock signal of the CRTC 41, a clock signal of the serial data signal sent to the video controller 53, and a timing signal for controlling the gate opening / closing of the multiplexer 43. Reference numeral 43 is a multiplexer having a function of switching the address signal from the MPU 31 and the address signal from the CRTC 41 according to the timing signal from the timing signal generator 42. Reference numerals 44 to 46 are graphic memories for storing display data of each color element of the display unit 7, red, blue, and green, and read / write operations from both elements of the MPU31 and CRTC41 via the multiplexer 43 are possible. It is possible to display eight types of data in different colors by combining the three primary color data. Reference numeral 47 is a memory dedicated to character data necessary for displaying character information on the display unit 7, and is a character memory capable of performing read / write operations from the MPU 31 and CRTC 41 and both elements via the multiplexer 43. 48 is an alphanumeric character,
A charactor generator that stores patterned character information such as symbols and katakana.
Character information corresponding to the character data read from 47 is selected and output. 49 to 52 are graphic memory 44 to 46
And a converter for converting parallel data output from the charactor generator 48 into serial data in synchronization with the timing signal generated from the timing signal generator 42. Reference numeral 53 is a video controller that performs level conversion and waveform shaping processing on the output data of the conversion units 49 to 52 in accordance with the required specifications of the display unit 7, and the display data is sent from the video controller 53 to the display unit 7. An amplifier 8 (FIG. 1) is connected to the interface 54.

 Next, the operation of this embodiment will be described.

For example, it is assumed that Japan with a predetermined scale is divided into a large number of blocks, and a number is given to each road map (hereinafter referred to as a block map) for each block. In addition, this block number consists of two-digit numbers, and for block maps lined up in the east-west direction, the lower digit of the block number is 0,1,2,3 ... from the west side to the east side.
In the block map arranged in the north-south direction, the numerical value of the upper digit of the block number is different from the north side to the south side, 0, 1, 2, 3 ,. Here, it is a map book separately showing each block map, and before driving, the block map including the traveling start time can be found from this map book. Also,
In the external storage device 6, together with the information of these block maps and data of various driving conditions, for each of these block maps, road map information indicating a complicated area of roads such as an urban area and having a small scale factor (Hereinafter, referred to as enlarged map) and various traveling conditions for this enlarged map information are also stored.

First, when the ignition switch is turned on, when the ignition switch is turned on, the system including the MPU31 shown in FIG. As a result, the system is in a command receiving state by the operation of each switch 11-18 on the operation switch unit 5. In that state, when the driver or the like operates any of the switches 15 to 18, the switch signal thus shaped is waveform-shaped by the interface 39 and then the MPU 31 via the input / output control circuit 34.
Is taken into. As a result, after the initialization, the MPU 31 first causes the switches 15 to 18 to have a function for designating a block map.

At this time, when the switch 15 is operated, the upper digit of the block number is decreased by 1, and when the switch 17 is operated,
The upper digit of the block number is incremented by 1. With this, the block map to be designated can be changed in the north-south direction. When the switch 16 is operated, the lower digit of the block number is decreased by 1, and when the switch 18 is operated, the lower digit of the block number is increased by 1. With this, the block map to be specified can be changed in the east-west direction.

Therefore, knowing the block number of the block map including the starting point from the map book, and in order to specify the desired block map, operate switches 15 to 18 to enter this block number, and then operate switch 11. This switch 15
Block number signal from operation 18 to interface 39
Also, it is taken into the MPU 31 via the input / output control circuit 34.
As a result, the MPU 31 sends a block map information call command signal designated by the switches 15 to 18 to the external storage device 6 via the CMTC 35 and the interface 40. In response to the call command signal, the external storage device 6 sends the corresponding block map information and various traveling conditions to the block map information through the interface 40 and the CMTC 35.
46, and send to the character memory 47, respectively. An address signal is supplied from the MPU 31 to the graphic memories 44 to 46 and the character memory 47 via the multiplexer 43.
As a result, the red display data of the block map information is stored in the graphic memory 44, the green display data is stored in the graphic memory 45, and the blue display data is stored in the graphic memory 46. At the same time, character data of various traveling conditions is stored in the character memory 47 in the character memory 47.

When the storage of the data in the graphic memory 44 to 46 and the character memory 47 is completed, the graphic memory 44 to 46 and the character memory 47 are brought into the read mode by the CRTC 47, and the address sent from the CRTC 47 via the multiplexer 43. In response to the signal, the block map information is read from the graphic memories 44 to 46, and the character data is read from the character memory 47. The primary color information of the block map information is sent to the conversion units 49 to 51, respectively, and is also stored in the character memory.
The character information output from the character generator 48 according to the character data read from the 47 is sent to the conversion unit 52, and is parallel / serial converted by the timing signal from the timing signal generation unit 42, and then the video It is sent to the display unit 7 via the controller 53.

As a result of the above operation, the road of the designated block map is displayed on the display unit 7 by the block map information as shown in FIG. 4, and the road name 406,407,408,409,41 is displayed.
0 or the like is displayed according to the data of various traveling conditions. At the same time, on the displayed road map, an area 403 to be displayed on the enlarged map and intersections 404 and 405 between the area 403 and the road are also displayed, such as an urban area. Also, horizontal and vertical cursors are displayed.

In this way, when the designated block map is displayed, the MPU 31 causes the switches 15 to 18 to have a cursor operation function. When the switches 15 and 17 are operated, the horizontal cursor moves vertically on the block map displayed on the display unit 7. When the switches 16 and 18 are operated, the vertical cursor moves horizontally.

Therefore, next, the driver operates the switches 15 to 18 while looking at the displayed road map to bring the intersection of the cursors to the traveling start point. Then, when the switch 11 is operated,
Data accompanying this is supplied to the MPU 31 via the interface 39 and the input / output control circuit 34, and is stored in a specific address of the RAM 32 as position data representing the position of the map (hereinafter referred to as travel start position data). . Then, this position data is read out from the RAM 32 and is transferred to the graphic memories 44 to 4
It is supplied to 6 and written in the block map information in duplicate. As a result, in the display unit 7, as shown in FIG.
The traveling start point 400 is displayed on the road map. Along with this, the cursor disappears.

Next, the driver looks up the block map including the travel destination point with the atlas and knows the block number.
This block number is set by the operation of .about.18, and then the switch 12 is operated. As a result, the MPU 31 reads out the block map information of the specified block number and the various running conditions corresponding to it from the external storage device 6 as in the case of the block map including the running start point, and stores them in the graphics memory 44. ~ 46 and character memory 47 are stored. Therefore, on the display unit 7, as in the previous case,
A block map including the destination point and horizontal and vertical cursors are displayed. Then, as in the above description, the driver operates the switches 11 to 18 by operating the switches 15 to 18 so that the intersection of the cursors is aligned with the destination point on the displayed road map. As a result, position data corresponding to the travel destination point (hereinafter referred to as travel destination point position data) is stored in another specific address of the RAM 32, and this position data is also written in the graphic memories 44 to 46. As shown in FIG. 4, the travel destination point 401 is displayed on the road map. Along with this, the cursor disappears.

When the position data of the traveling start point and the traveling destination point are stored in the RAM 32 as described above, the MPU 31 again stores the block map information including the traveling start point and the data of various traveling conditions from the external storage device 6. The data is read out, and the road map is displayed on the display unit 7 together with the travel starting point from the position data of the travel starting point read from the RAM 32.

In addition, the MPU 31 takes in the scale ratio data of the various traveling conditions read from the external storage device 6, and based on this data, the block map displayed on the display unit 7 is displayed on the display screen. The actual distance corresponding to the unit length of is calculated. The obtained distance data is stored in a specific address of the RAM 32 and is written in the graphic memories 44 to 46 and the character memory 47, and as a result, it is displayed at a predetermined position on the block map displayed in FIG. As shown in, the actual distance per unit length on the display screen is displayed.In this example, a block map with a scale of 1 / 1,000,000 has a symbol 411 with a length of 1 cm and the corresponding actual distance. "10k" that represents distance
The numbers and symbols of "m" are displayed.

In addition, in FIG. 4, the traveling start point 400 and the traveling destination point 4
It is shown that 01 and 01 are included in the same block map, but when they are included in different block maps, the travel destination point 401 is naturally not displayed.
Even if the block map including the traveling start point and the block map including the traveling destination point are the same, it goes without saying that the above operation is performed for each point. In order to distinguish them, a switch 12 different from the switch 11 is provided for the operation related to the traveling destination point.

After that, the block map information including the traveling start point and the various traveling conditions corresponding thereto from the external storage device 6 and the reading of the position data and the distance data of the traveling start point from the RAM 32 are repeatedly performed at regular intervals. As a result, the data is rewritten in the graphic memories 44 to 46 and the character memory 47, and the road map including the travel start point 400 is displayed on the display unit 7 as the unit timetable time symbol 411, etc. Is displayed together with.

When the vehicle starts traveling, the direction sensors 2 and 3 and the vehicle speed pulse sensor are taken into the microcomputer unit 1, and the traveling direction of the vehicle is detected from the vehicle speed pulse sensor 4 based on the traveling direction data from the direction sensors 2 and 3. The total distance traveled by the pulse accumulation of
The current position data of the automobile is calculated from the traveling start point data stored in. This current position data is RAM3
It is stored in the second specific address (which may be the address in which the traveling start point data is stored), and is read from this and written in the graphic memories 44 to 46. The data of the azimuth sensors 2 and 3 and the pulse output from the vehicle speed pulse sensor 4 are fetched into the MPU 31 at the above-mentioned constant time intervals, and new current position data is obtained each time the RAM 32 is read.
To memory and read from it. Graphic memory 44
Writing to ~ 46 is repeated. Therefore, in the display unit 7, as shown in FIG.
Is also displayed, and this current point 402 moves as the automobile runs.

Therefore, in FIG. 4, the vehicle is now traveling on the road 406, and when the current point 402 reaches the boundary point 404 of the area 403 thereafter, the MPU 31 detects this and the displayed map of the block map is displayed. Instead, the external storage device 6 reads the enlarged map information representing the area 403 and various traveling conditions for the enlarged map information. As a result, the same processing as in the case of the block map is performed, and the display unit 7 displays the fifth
As shown in the figure, an enlarged map for the area 403 (Fig. 4) is displayed. Also at this time, the distance data obtained from the scale factor of the enlarged map indicates that the symbol 414 representing the unit length and the numbers and characters representing the actual distance corresponding to this length are displayed at a predetermined location on the displayed enlarged map. Is displayed. Here, the scale of the enlarged map is set to 1 / 100,000, and the symbol 414 is displayed as 1 cm, which represents "1 km".

When the current position 402 reaches the edge on the display screen, MPU31
Detects this, and if the enlarged map was displayed on the display screen, the original block map will be displayed,
When the block map is displayed, the block map information adjacent to the displayed block map and the data of various driving conditions are read from the external storage device 6, and so on. Then, the block map or enlarged map including the current position 402 is always displayed on the display unit 7.

〔The invention's effect〕

As described above, according to the present invention, even if the displayed road map changes, the actual distance per unit length of the display screen according to the scale factor is displayed on the road map. Therefore, it is possible to obtain an excellent effect that the sense of travel distance can always be easily grasped and the driving labor can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the navigation system according to the present invention, FIG. 2 is a block diagram showing one specific example of the operation switch unit in FIG. 1, and FIG. 3 is a microcomputer unit in FIG. Block diagrams showing a specific example, and FIGS. 4 and 5 are explanatory diagrams showing display examples on the display section in FIG. 1 ... Microcomputer part, 2, 3 ... Direction sensor,
4 ... Vehicle speed pulse sensor, 5 ... Operation switch part, 6 ...
… External storage device, 7 …… Display unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Tsujii 1410 Inada, Katsuta City, Ibaraki Prefecture 1410 Inada, Hitachi, Ltd. Car Audi Obi Visual Factory (72) Inventor Kazuhiro Watanabe 1410 Inada, Katsuta City, Ibaraki Prefecture Hitachi Car Audio Visual Factory (56) Reference JP-A-57-73498 (JP, A) JP-A-56-74798 (JP, A)

Claims (1)

[Claims] 1. A navigation system in which the current position of a moving vehicle is displayed on a road map displayed on a display unit, and a plurality of block road maps showing different regions with a first scale ratio are displayed. Road map information showing the block road map information and the enlarged map information showing a part of the preset specific area on the block map represented by the block road map information at a second scale And storage means for storing the block road map information and scale factor data for each of the enlarged road map information, and scale factor data for the road map displayed on the display unit are read from the storage means, and Calculating means for generating distance data representing an actual distance corresponding to a unit length on the screen of the display unit according to the scale factor; and a road map displaying the distance data. Display control means for displaying on the display unit, and the road map displayed on the display unit is the block road map, and the specific area on the block road map in which the current position of the moving body is displayed. Position detection means for detecting this, and based on the detection by the position detection means, reading from the storage means the enlarged road map information and the scale factor data for the detected specific area. And a means for instructing the calculation means and the display control means to display the enlarged road map and the distance data for the scale factor data on the display section, and the road displayed on the display section. The actual distance corresponding to the unit length on the screen of the display unit is displayed on the map, and when the moving body reaches the specific area on the displayed block road map, the display on the display unit is displayed. The specific ward Scan navigation system, characterized in that the change in the enlarged road map for.