JP2569682B2 - Navigation system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a navigation system for displaying a road map to a driver of a traveling vehicle to guide the driver to a destination, and in particular, to a current position while traveling. Automatic display technology for road maps.

(Prior Art) As is well known, a navigation system that displays a road map to a vehicle driver and guides the driver to a destination is known as,
Conventionally, various types have been proposed. The problem with this type of navigation system is how to determine the current location of the vehicle. Conventionally proposed methods include, for example, detecting the traveling direction of the vehicle using a gyro compass, And a method of calculating the current position of the vehicle from the steering angle and the traveling distance of the vehicle, and the like.

(Problems to be Solved by the Invention) However, in the above-described method for calculating the current position of the vehicle, an error is likely to occur when traveling over a long distance because the calculation process includes an integral calculation process.

Therefore, in the conventional navigation system, an erroneous road map may be displayed during long-distance traveling, and there is a problem that the driver must correct each time.

The present invention has been made in view of such problems,
An object of the present invention is to provide a navigation system that can automatically display a road map of a vehicle traveling point.

(Means for Solving the Problems) In order to achieve the above object, the navigation system of the present invention has the following configuration.

That is, the navigation system of the present invention is a navigation system for guiding a traveling vehicle to a destination; this navigation system is provided at each intersection of partition lines that divide the ground at equal intervals in east, west, and north and south directions. Two intersections that generate one of the nine types of radio waves at the position and are adjacent to each other in nine types of identification numbers assigned to the nine types of frequencies in which the nine types of radio waves are generated A terrestrial system in which a difference value between identification numbers of frequencies of radio waves generated at positions is set so as to satisfy a certain requirement; a display means for displaying a road map; The storage means for storing road map data and the road map data determined by the difference between the frequency identification numbers before and after the change in the frequency of the received radio wave are read from the storage means. It is characterized in that is constituted by; a vehicle system comprising a control means for controlling the road map displayed on the display means in a.

(Operation) Hereinafter, the operation of the present invention having the above configuration will be described.

The direction from one intersection position to another adjacent intersection position at each intersection position of the partition line dividing the ground at equal intervals in the east, west, north and south directions is east, northeast, north, northwest, west , Southwest, south and southeast. Radio waves of nine different frequencies generated by the ground system can be identified in these eight directions.

That is, in the in-vehicle system, the difference between the identification numbers of the frequencies before and after the change is determined in accordance with the change in the frequency of the received radio wave, that is, one of the eight directions is specified, and the specified direction is specified. Is displayed. There is no error in the displayed road map.

In this way, the driver is automatically displayed on the road map of the vehicle traveling point one by one.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration example of a ground system and a principle of a navigation system according to the present invention.

In FIG. 1, this ground system is one of nine numbers from 0 to 8 in accordance with rules to be described later at each intersection position of a partition line dividing the ground at equal intervals in the east, west, north and south directions. Is given as an identification number, and a radio wave of a frequency corresponding to the identification number is generated at each intersection position.

The identification number assigned to each intersection position is determined as follows. The direction from one intersection point to another adjacent intersection point is east, northeast, north, northwest, west,
There are eight directions: southwest, south, and southeast.
Therefore, in the present invention, a predetermined identification number is assigned to each intersection position so that the eight types of directions can be specified by the difference value between the identification numbers of the frequencies of the radio waves generated at two adjacent intersection points. For example, as shown in FIG. 2, the identification number assigned to one intersection position a has a difference value of “+1” from the identification number of the adjacent intersection position in the east direction, and “+” in the northeast direction.
4 "," +3 "in the north direction," +2 "in the northwest direction," -1 "in the west direction," -4 "in the southwest direction," -3 "in the south direction, and" -2 "in the southeast direction. It is determined as follows. At this time, in the present embodiment, 9 of numbers 0 to 8 is used.
The seed number is used as the identification number. When the difference value exceeds “+4”, a value obtained by subtracting the value 9 from the difference value is set as a value indicating the direction. Similarly, when the difference value exceeds “−4”, a value obtained by adding the value 9 to the difference value is set to a value indicating the direction.

In FIG. 1, the identification numbers set at the respective intersection points are determined in accordance with the above rules, and indicate the frequency arrangement without being corrected.

Next, FIG. 3 shows an example of the configuration of a vehicle-mounted system. In FIG. 3, 20 is an antenna, 21 to 29 are bandpass filters, 30 is a comparator, 31 is a minuend register, 32 is a subtraction register, 33 is a subtractor, 34 is a map control unit, 35 is a storage unit, and 36 is a storage unit. It is a map display section.

The radio wave received by the antenna 20 is composed of various frequency components.
Bandpass filters 21 to 29 that perform filtering processing for each of the nine frequencies corresponding to the same 8 decompose into signals of the respective frequency components and add the signals to the comparator 30.

The comparator 30 sets a threshold power level _PT . First, an input signal indicating the maximum level among input signal power levels exceeding the threshold power level _PT is detected, and an identification number a of the frequency of the input signal is detected. Is set in the minuend register 31.
Then compared When radio frequency identification number b in addition to the identification number a is received as the largest ones beyond the threshold power level P _T, the received power P _a of the two waves, the magnitude relationship between the P _b , set the contents of the control signal to the P _b ≦ P _a + P _T between which the map controller 34 as a road map is status quo to be displayed on the map display unit 36.

Then, P _b ≦ P _a + P _T at the same time P _b> P _a + at the time of the change to the P _T for transmitting the effect of the subtractor 33 and the map controller 34 navel from subtrahend register the identification number a set in the minuend register 31 At the same time, the identification number b is set in the minuend register 31.

The subtractor 33 receives the instruction from the comparator 30 and performs a b−a operation on the value b of the minuend register 31 and the value a of the subtrahend register 32, and transmits the result to the map control unit 34.
The contents of the subtraction register 32 are changed from the value a to the value b to prepare for the next change.

The storage unit 35 stores in advance the road map data for each area partitioned at equal intervals shown in FIG. The storage unit 35 may be subordinate to the map display unit 36, but is shown as subordinate to the map control unit 34 in FIG.

The map control unit 34 determines the direction shown in FIG. 2 based on the calculation result, reads out road map data for a predetermined area from the storage unit 35, and causes the map display unit 36 to display a road map. Note that the operation result of the subtractor 33 is a value “+4”.
As described above, a value obtained by adding the value “−9” to the above is a value indicating the direction, and a value obtained by adding the value “+9” is a value indicating the direction when the operation result is the value “−4” or more. It is on the street.

Next, display control for the map display unit 36 will be described with reference to FIG. In FIG. 1, reference numeral 11 denotes a road, and it is assumed that a vehicle 12 is running on the road 11 in the direction of the arrow shown in FIG. For example, in a case where a road map of four regions indicated by reference numeral 13 is displayed on the map display unit 36, when the vehicle 12 approaches the turning point of the road 11, the calculation of "3-1 = + 2" is performed, and The four areas of the road map indicated by 14 are changed and displayed on the map display unit 36. Then, when the vehicle 12 passes through the turning point of the road 11, a calculation of "7-3 = + 4" is performed, and
The four areas of the road map indicated by are changed and displayed on the map display unit 36.

As described above, a predetermined road map is automatically displayed on the map display unit 36 in such a manner that the road map partially overlaps with the progress of the vehicle. It goes without saying that how the display range of the map display section 36 is determined is arbitrary.

(Effects of the Invention) As described above, according to the navigation system of the present invention, radio waves of nine types of frequencies are present at the intersections of partition lines that are equally spaced in each of the east, west, and north and south directions on the ground. A terrestrial system that generates one and determines the frequency arrangement so that the direction can be specified by the difference values of the nine types of frequency identification numbers is provided, and the on-vehicle system generates a road map corresponding to a change in the reception frequency. Since it can be displayed,
There is an effect that a road map of a point where the vehicle is currently traveling can be automatically and accurately displayed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a terrestrial system and a principle of a navigation system of the present invention, FIG. 2 is a diagram illustrating a relationship between frequency allocation and direction, and FIG. 3 is a configuration block diagram of a vehicle-mounted system. Numerals 0 to 8 Identification number of radio wave frequency generated at that point, 11 Road, 12 Vehicle, 13 to 15 Display range, 20 Antenna, 21 to 29 Bandpass filter ,
30 Comparator, 31 Subtractor register, 32 Subtractor register, 33 Subtractor, 34 Map control unit, 35 Storage unit, 36 Map display unit

Claims (1)

(57) [Claims] 1. A navigation system for guiding a traveling vehicle to a destination, the navigation system comprising nine types of partition lines at the intersections of dividing lines dividing the ground at equal intervals in east, west, and north and south directions. One of the radio waves of the frequency is generated, and the generation mode of the radio waves of the nine frequencies is generated at two intersection points adjacent to each other with the nine identification numbers assigned to the nine frequencies. A ground system in which a difference value between identification numbers of radio wave frequencies is set to satisfy a certain requirement; a display means for displaying a road map; and road map data for each area divided at equal intervals. The road map data is displayed on the display means by reading out from the storage means the road map data determined by the difference between the identification numbers of the frequencies before and after the change in accordance with the change in the frequency of the received radio wave. And an in-vehicle system having control means for controlling the navigation system.