JPS59231410A - Recording device of data on map for navigation system - Google Patents

Abstract

PURPOSE:To reduce the time required for searching a corresponding map or enlarged map by a system wherein an area held between inter-record gaps (IRG) for indexing is determined as one block on a magnetic tape, and map informations on one original and one enlargement of a displayed map are recorded as one set of map informations in said block. CONSTITUTION:A magnetic tape has such recorded areas as a soundless IRG signal portion IRG1, an enlarged-map position information portion D1 provided additionally with an information on a matrix position at which an enlargement of the original map is inserted, i.e. the data showing the position number of the IRG signal portion on the right or left on the tape, to which said enlargement is adjacent, an original-map data portion M1 in which the map data for one picture are recorded, an enlargement data portion LM1 in which the map data on the enlargement for one picture are recorded, and another soundless IRG signal portion IRG2. The area held between the IRG signal portions IRG1 and IRG2 in this way is determined as one block. Thus, the two data on the original map and the enlargement thereof can be made to correspond to one IRG signal respectively, and a desired number of enlargements are inserted between the original maps without disturbing the regularity of the original maps. This constitution enables the high-speed retrieval of the original of the displayed map and the enlargement thereof which are necessary for a navigation system, and consequently a time required for retrieval of a map can be reduced.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a map data recording device used in a navigation device, and is particularly applicable to a navigation device in which the displayed map is frequently switched between an original map and an enlarged map. The present invention relates to a map data recording device suitable for use.

[Background of the invention]

As a navigation device that detects the current position of a car and displays a road map corresponding to the current position, the current position, and information necessary for driving, for example, Japanese Patent Application Laid-Open No.
A "vehicle navigator" disclosed in Japanese Patent No. 201808 is known. In this method, map data for displaying a specific road map and map data with different scales for the specific road map are stored in the means described in 1.1. Then, in response to an instruction to change the scale of the road map, map data of a road map with a different scale from the currently displayed road map is read from the storage means, and the road map is displayed on the display means. In the above known example, a cassette tape is used as a storage means for storing map data. This cassette tape is an inexpensive recording medium, and in recent years, many cars are equipped with music cassette decks, so it has been proposed that such music cassette decks can also be used as map data playback devices. has been done.

However, in the above-mentioned known technology, the map number, absolute coordinate data, scale, scale, etc. A header section formatted in the order of map number and enlarged map number and a map data section necessary for displaying the road map are recorded. However, with this type of recording, a problem arises when the map information is read out from the magnetic tape using a cassette deck.

This is because when searching for a map number, the magnetic tape is read out at normal playback speed, so as long as the map number is being searched, the map number can be read while playing, so there is no problem with the map search function. The speed of finding the map becomes slower. This is because, in the device of the above-mentioned known example, the map information must be sequentially read and judged at the normal playback speed until the target map is found, and the tape reading speed is limited to the above-mentioned normal playback speed. Put it away. In this case, the time required to search varies depending on the location of the map information to be searched, but in general, the search takes time on the order of several minutes to several tens of minutes, which is impractical as a navigation device. be.

Therefore, in order to solve the above-mentioned problems, it is being considered to perform map searches at high speeds such as fast-forwarding and fast-rewinding.
In general, as long as a cassette deck is used, it is dependent on the performance of the reading device and is not actually possible.

In a navigation device, for example, when the current position of a vehicle exceeds a map on a display screen, the displayed map must be immediately rewritten to a map that matches the current position of the vehicle. However, as mentioned above, when rewriting a map, the conventional retraction device of the navigation device sequentially reads out unnecessary information in the header at the normal playback speed, wasting time rewriting the map. , it becomes impossible to instantly rewrite the map.

This becomes a serious problem, especially in navigation devices that have a map enlargement display function. When a vehicle enters a complex part of the road, such as in an urban area, an enlarged view of the original map is required. At this time, the map will be rewritten more frequently, but as in the case of map rewriting described above, the reading device sequentially reads out the enlarged map numbers from the header portion of each map information at the normal reading speed. If you select the corresponding map data from this read number and read out the enlarged map data corresponding to the enlarged map number from the map data section, it will take too much time to read out the desired enlarged map data, so you will not be able to rewrite the displayed map. It becomes impossible to perform rewriting within the allowable time when displaying an enlarged map, which is a major drawback for a navigation device having an enlarged/reduced map.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems of the prior art, and aims to shorten the time required to rewrite the original map or enlarged map of a displayed map, particularly the time required to search for a corresponding map or enlarged map. The present invention provides a map data recording device for a navigation device.

[Summary of the invention]

According to the present invention, on a magnetic tape of a map data recording device for a navigation device, a portion surrounded by an inter-record gap (IRQ) for cueing is defined as one block, and an original map and an enlarged map of the displayed map are divided into one block. Each map/IR report is recorded as one set of map information.

[Embodiments of the invention]

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

FIG. 1 shows the overall configuration of a navigation device according to the present invention. In the figure, a mileage detector 1 detects, for example, the rotation of a permanent magnet attached to an axle that moves with an axle using a pickup coil, and generates a pulse signal corresponding to the vehicle speed. The traveling direction detector 2 is a detector that detects the traveling direction of the vehicle. For example, it is a magnetic sensor that detects the traveling direction using earth (magnetism), and is called a flux gate method. The absolute direction is determined by the ratio of the voltage Vx and VrO generated in the wound coil.The signals detected from the traveling distance detector 1 and the traveling direction detector 2 are read into the signal processing device 3. The signal calculation processing device 3 calculates the current driving position of the vehicle by calculating the current driving position of these two signals.The signal calculation processing device 3 also calculates the current driving position and Map data commensurate with information 1
．． is input from device 4. A cassette tape recorder is used as the TW information storage device f4. Then, this signal processing device 3 compares the current traveling position with the information in the information storage device 4,
A road map, an accurate current driving position on the road map, and other road information are superimposed and displayed on the screen of a display device tt5 consisting of a CRT (CRT). The operator inputs commands from the keyboard 6 to set the current location 1e1 destination, etc.

Next, the navigation device will be further explained in detail using the block diagrams shown in FIGS. The mileage detector 1, the traveling direction detector 2, the cassette deck 4, and the keyboard 6 are connected to the signal processing device 3. The output from the signal processing device 3 is connected to C and RT5 via a deflection circuit 51. The system described above is controlled by a micro-grossing unit (MPU) 37. The MPU 37 has a read-only memory (i(
, OM) 321, according to the program stored in
Perform the action. random access memory (RAM)
) 322 is the stack or buffer of the MPU 37.
Used as memory.

When initializing the system, the operator must press the keyboard 6
Data regarding the current location etc. is input from the . Based on this data, the MPU 37 controls and drives the Kasetsu Todetsuki 4 to search for necessary map data, and transfers the map information to the video RAM (VR, A
M) Transfer to 34. The map information written in the video RAM 34 is
The signal is converted into a signal format that can be displayed on the CRT 5, and then sent to the deflection circuit 5.
1 and is supplied to the C ratio T5. An oscillator (O8C) 31 is connected to the CR, T controller 35 as an auxiliary circuit.

The current position of the vehicle can be determined from the direction of travel and distance traveled. The output of mileage detector 1 is input/output (Ilo)
It is read into the MPU 37 via the boat 38. Output voltage Vx of the traveling direction detector 2.

After Vy is converted into a digital signal by an analog/digital (A/D) converter 39, it is read into the MPU 37 via an input/output (10) port 38.

A map as shown in FIG. 3 is stored on the cassette tape. The map is divided into a matrix and numbers are assigned according to rows and columns, and by assigning numbers in this way, it becomes easier to search the map according to the movement of the car. In other words, in Figure 3, if the current position M (m, n) is protruding southward from the map, one row element is added to M.
All you have to do is find a map of (m+1, n). Similarly, the numbers of maps in eight directions adjacent to the map of the current location can be immediately known.

In reality, such map information will be one-dimensionally arranged and recorded on a cassette tape. Generally, in one block surrounded by an unrecorded part, that is, an inter-record gap (IRQ), there is a header part indicating the beginning of data, a map number part, and a map information part. , the ender part indicating the end of the block is recorded as one piece of map information. Therefore, the number assignment method shown in Figure 3 is used to calculate how many slots in which direction the target map is located on the tape from the recording location of the currently displayed map, and the position on the tape ( A method is being considered in which the number of IRQ signals is detected in a high-speed state and a map search is performed. Here, as a method for detecting the IRQ signal, for example, there is a method in which a non-recording section of about 3 seconds is provided as an IRQ signal during normal playback, and the number of the non-recording section is detected in a high-speed state.

According to the above method, a target map data block can be searched at high speed. However, if further enlarged map data is inserted using this method, a problem will arise in map retrieval.

That is, an IRQ signal is attached to each of the original map and the enlarged map,
If an arbitrary number of enlarged maps are inserted between the original maps, the regular matrix-like arrangement of the original maps will be disrupted, and it will no longer be possible to search for the desired map based on the number of IRGs alone.

The present invention rationally solves the above problems,
This will be explained in detail with reference to FIG.

FIG. 4 shows an embodiment of the magnetic tape for map data according to the present invention. In this embodiment, the magnetic tape 52 includes an IRQ signal part In, Gl consisting of a silent part, a header part H2 indicating the beginning of the map data of the original map, an original map number part Nl indicating the matrix position of the original map, and Data indicating the matrix position where the enlarged view is inserted, that is, the number 111 on the left and right on the tape, adjacent to the G signal section (magnetic head number, tape feeding direction, ■RG @ number,
An enlarged map position information section D1 to which an enlarged map number, etc.) is added, an original map data section M1 that records the map data screen, an ender section E1 that indicates the end of data reading, and an enlarged map that records the map data screen of the enlarged map. a data section LMI, an enlarged map number section N2 that indicates the number of the enlarged map, a header section H3 that indicates the beginning of the map data of the enlarged map, an IRQ signal section IRG2 consisting of a silent section,
It is recorded as follows. The area surrounded by the above-mentioned IRQ signal parts IRGI and IIRG2 becomes one piece of map data on the matrix as one block cup 1, and block A2 becomes the next map data on the matrix. By associating each block with the position of the matrix in this way, it is possible to insert an enlarged map without disrupting the regularity of the map arrangement of the matrix. The data M (m, n) regarding the original drawing has a reading direction R1, and the data LMI (m, n) regarding an enlarged drawing has a reading direction R2.
and record with the reading direction reversed. This makes it possible to easily read two types of data (original view; enlarged view) by searching for one IRQ signal section. Here, the original drawing number part N1, the enlarged drawing position information part DI, and the enlarged drawing number part N2 are referred to as label data.

FIG. 5 shows an example of the recording format of the original map and enlarged map of map data in a matrix. 'First, the original figure a(1,1) in Figure 5 is an enlarged figure <a 1>, <a 2>,
<a 3> is required, and the element diagram b (1, 2), c (1
, 3), d (1, 4) do not require an enlarged view. And the original map e(1,s) is an enlarged map <el>, <11!2>
need.

These original views are then recorded as a pair with the enlarged view. The original figure a (1, 1) is an enlarged figure <al> and the original figure b (
1, 2) is an enlarged drawing <R2>, and the original drawing C(1, 3) is an enlarged drawing <R3>. The respective original drawings are recorded in sets as shown in FIG. 5. Here, the enlarged drawing △> means that there is no corresponding original drawing, so nothing is recorded as data.

FIG. 6 shows the original and enlarged views shown in FIG. 5 recorded on a magnetic tape. Hereinafter, a method for searching map data will be explained using FIG. 6.

First, assume that the vehicle is traveling on the map recorded in the original map f(2,1) of FIG. Then, the magnetic head 5
3 is located in the ender section between IFI and G section 6 and 17 on the magnetic tape in FIG.

Next, when the vehicle moves from the original figure f (2, 1) to the original figure g (2, 2), the magnetic head 53 moves in the right direction 1 on the magnetic tape.
Detect the IRG section I7 in fast forward mode, and
). At this time, the original map g (2, 2) is an enlarged map <gl> according to the enlarged map position information section included in the original map g (2, 2).

<g2>, <g3> + <g4
It can be seen that there are five enlarged views of > + < g s >. Enlarged view gl> is the first left II (, G part I7) of the original figure g (2, 2), enlarged view g
2> is the first work on the right ■'LG section work 8, enlarged view〈g3〉
By searching the second IRG section ■9 on the right, enlarged drawing g4> searches for the third It (, 0 section 110 on the right), and enlarged drawing g5> searches for the fourth IRG section Ill on the right. , each enlarged view can be searched at high speed.

For example, if you want an enlarged view <g3>, use the magnetic head 5.
3 detects the second IR, G section ■9 on the right, and enlarged view <g3
> to the left. In FIG. 6, the enlarged view 〈△〉 is drawn as if it were recorded, but it does not actually exist on the magnetic tape; that is, the tape length can be shortened by this amount of data.

By doing this, one IRQ signal can be associated with two pieces of data: the original map and the enlarged map, and
It becomes possible to insert an arbitrary number of enlarged drawings between original drawings without disturbing the regularity of the original drawings. Furthermore, since the original map maintains a regular arrangement, even if a data error occurs, the desired map position can be immediately calculated by reproducing the original map number m. and,
Since the IR and G signal portions, which account for a large proportion of the data length, can be made to correspond to two map data, there is also the effect of increasing the data recording density. Furthermore, since the insertion of an enlarged view does not disturb the arrangement of the original map, inserting or erasing an enlarged view of a series of map data requires only changing that part, making it easier to create a map tape.

〔Effect of the invention〕

According to the map data recording device for a navigation device according to the present invention, as is clear from the above description, the original map and enlarged map of the display map necessary for the navigation device can be searched at high speed. It is a practical and useful navigation device, as it reduces the time required for rewriting the map display and there is no delay in rewriting the map display.
In particular, it is possible to provide a device having a map enlargement display function.

[Brief explanation of the drawing]

Figure 1 is an overall configuration diagram of the navigation device, Figure 2 is a block diagram showing the circuit configuration of the navigation device, Figure 3 is a diagram explaining the division and configuration of a display map, and Figure 4 is map data according to the present invention. FIG. 5 shows the arrangement of recorded data on the magnetic tape of the recording device. FIG.
FIG. 2 is a diagram showing a recording form of an original view and an enlarged view in the figure recorded on a magnetic tape.

Claims (1)

[Claims] 1. Detect the traveling distance and traveling direction of the vehicle, calculate the current position of the vehicle, read out map data corresponding to the current position, and display the map and the current position of the vehicle on the display means. used in navigation devices that simultaneously display
The area surrounded by inter record gaps is 1
1. A map data recording device for a navigation device, characterized in that the map data is a block, and an original map and an enlarged map are recorded as one set of map information in the block. 2. The map data recording device for a navigation device according to claim 1, wherein the map data of the original map and the enlarged map recorded on the magnetic tape are recorded in opposite directions. 3. Claim 2 states that label data such as map numbers attached to the original map and enlarged map in each block are placed on the inter-record gap side with respect to the original map and the enlarged map, respectively. Features: Map data recording device for navigation devices. 4. The map data recording device for a navigation device according to claim 1, wherein the enlarged view recorded in the block is arranged close to the original view that requires the enlarged view. 5. The map data recording device for a navigation device according to claim 1, wherein when the block does not require an enlarged view, the enlarged view recording section is omitted. 6. A map data recording device for a navigation device according to claim 1, characterized in that a map data twin record gap is searched at high speed.