JPS62142214A - Travel guide for vehicle - Google Patents

Abstract

PURPOSE:To provide information in the neighborhood of the present place corresponding to accuracy by selecting and displaying a scale of a map displaying the present position corresponding to the present position detecting accuracy of a present place detection means (GPS). CONSTITUTION:A storage means 12 stores plural maps with different scales. Then, an electric wave from a satellite is received by a receiver of a position measuring means (GPS) of the present place detection means 14 to detect the present position of a vehicle. One is selected out of the plural maps with different scales of the means 12 by a control means 16 according to the size of degradation calculation (GDOP) of the GPS and information (the present position of the vehicle and a target place) of travel guidance is displayed on a display means 10.

Description

[Detailed description of the invention] (Field of application in the L industry) This invention is based on the following features: ■ Vehicle 1 ■ Travel guidance! Regarding the device, in particular, it is possible to change the scale of the map on which the current position of the vehicle is displayed in accordance with the detection stone of the current position of the vehicle.
&:rm.

(Prior art) The Φ vehicle running guide) 95A ~ displays the vehicle's travel trajectory and current position ~ along with a road map of the area where the vehicle is traveling on a display means such as a CRT, and prevents the 1tI vehicle from reaching the destination by mistake. A device for guiding without any interference;
An example is shown in the publication.

This type of fraud has a current location detection means to detect the current location of the vehicle.
As disclosed in Publication No. 0, a means is provided for detecting the travel distance and direction of a vehicle from a certain reference point and grasping the current position of the vehicle as a relative position from the reference point fx+. There is.

However, this current location detection means has a disadvantage in that accuracy is low due to accumulation of measurement errors in travel distance and direction.

Therefore, a method has been proposed that receives radio waves emitted from a satellite and determines the current position of the vehicle as an absolute position on the earth ('ei<up degree, 17 degrees).

(Problems to be Solved by the Invention) The current location detection means using the above-mentioned Eikun is currently under development for global positioning ffi! System (Global (l)
.

This system is called 5itiOninO5vStel (hereinafter abbreviated as GPS), and this system is capable of measuring the current position of a vehicle with a maximum accuracy of about 20 meters by receiving radio waves emitted from multiple artificial satellites. .

However, the measurement accuracy of such current location detection means varies depending on the position of the star, the perturbation of the wifi, the state of the ionosphere, etc.

On the other hand, in the conventional vehicle driving guidance w# device, maps displaying the points detected by the current location detecting means are only prepared at the same scale.

For this reason, even if the current location could be measured with high precision, displaying it on a map of the same scale would not convey sufficient information to the user.

In other words, if the current position can be measured with high accuracy, more detailed information can be conveyed to the user by enlarging the map that displays it and displaying it in Ilk, but there is a problem that this cannot be supported. Ta.

This invention has been made in view of these problems, and its purpose is to select and display the scale of a map to display the current location in accordance with the measurement accuracy of the current location detection means, N1 dual-use driving tltIlvtli that can present information commensurate with accuracy! Our goal is to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an intermediate running Ei
The device includes a display means (a) for displaying information for guiding the vehicle, a storage means (b) for storing a plurality of maps of different scales, and a display means (b) for displaying information for guiding the vehicle. A current position detection means (d) having at least a positioning means (C) for detecting the current position; a deterioration coefficient detection means (e) for detecting a ranging error of the positioning means (C); a selection means (f) for selecting one of the maps stored in the storage means (b) in accordance with the magnitude of the deterioration coefficient detected by the display means (f); 1, II-Means shown in a) (g)
It consists of

Here, the above deterioration coefficient (Geo■e[rical Di
lutionOr Precision, abbreviated as GD
OP) is used to measure the current position8.
is a factor representing the increase in the measured wA difference determined by the geometric function between ft1l and the vehicle.

(Function) According to the Le dual-use traveling special equipment j with the above configuration, the current 1 ftm is displayed on the map with a scale corresponding to the measurement accuracy of the current location detection means, so for example, when the accuracy is good, It is possible to show the current location n on a greatly enlarged map and convey information according to the viscosity to the user.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 2 to 4 show the running X' for medium thickness according to the present invention.
4 shows an example of the device.

As shown in Figure 2, the 1st and 2nd dual use F1 and 9A cargoes shown in the same figure have information (E
Display means 10 for displaying the current position of one vehicle, target location, etc.
and a storage means 1 that stores a plurality of maps of different scales.
2, a current position detection means 14 having at least a positioning means (GPS) that receives the 1C wave from ll1jJ and detects the current position of the vehicle, and
), and a control means 16 for selecting one map from among a plurality of maps of different scales stored in the storage means 12 and displaying it on the display means 10 according to the size of the map.

The display means 10 is, for example, a monochrome or color CR.
T, liquid crystal display element, plasma display, electroluminescence, etc. are used, and the displayed information is as described in 21 above.
1111O means 16.

As the storage means 12, for example, a CD-ROM or a magnetic tape is used, and in particular, C and D-ROM are used.
Since f t'a is large, compact, and the access time is short, it is suitable as a storage means for mounting both φ.
In addition to the above-described map, information such as start-up inspection procedures and ear replacement procedures may also be stored. Information is retrieved from the storage means 12 by loading a recording medium such as a compact disc Yadev into the reproducing device and controlling the reproducing device by the control means 16.

The current location detection means 14 has the GPS as described above, but a known geomagnetic sensor may also be installed therein.

Below is a l1il that detects your current location using GPS! I!
I will explain about it.

As schematically shown in Fig. 3, the GPS is composed of a plurality of antennas A1 to A4 distributed at appropriate intervals of 1 m on the earth E, a plurality of antennas A1 to A4 (F)11i1S1 to S4, and a user P. and each WIi51-S4 has an antenna A1-A
&lI IE by 1110g4G via 4.

In addition, each satellite 81 to S4 has a receiver that receives signals from antennas A1 to A4, and a transmitter that emits various information signals to user P. ! $1~S4
and a receiver for receiving signals from the terminal.

Here, if there is a clock that is completely synchronized at the transmitting point and the receiving point of radio waves, and the transmitting signal is set to III tit by that clock, then if the timing of the reception is measured at the receiving point, the radio wave between the transmitting and receiving points can be measured. The propagation time can be determined, and by multiplying it by the speed of light, the distance between the transmitting and receiving points can be determined. Now, 311 is in the field of view (receivable area) of the IP being used.
Mamoru ff51, S2.

Assume that there is a satellite S3, that each of the satellites 81, 82 and S3 is transmitting ranging signals using clocks that are synchronized with each other, and that the position of each satellite 181 to S3 at the time of reception is accurately determined. If you measure the reception 11t1m of these signals at the reception point C, you will be fine! E! The distances between Sl, S2, S3 and the receiving station are determined, and the position of the 6P used is determined from each 11i1s1.
82, can be determined as the intersection of three spherical surfaces centered at S3.

However, in reality, it is difficult to completely synchronize the clocks at the transmitting point and the receiving point, and W4 due to delays in the received signal.
It makes a difference. In addition, in this system, as mentioned above,
The measurement accuracy fluctuates, including measurement errors due to positional errors of S1 to S4, state of Ti delamination, etc.
4 to user P&: The signal emitted also includes data on a degradation coefficient (GDOP), which is a coefficient indicating the magnitude of the measured WA difference.

Table 1 below is an example of the types and magnitudes of measurement errors that have been published, and by simply multiplying these numbers by GDP, it is possible to determine whether users are actually using this system. This allows you to check the accuracy of the case.

Table 1 On the other hand, above! In this embodiment, the means 16 is composed of a so-called microcomputer, and the display means 10. Storage means 12. Input/output interfaces 16a each connected to the current location detection means 14;
According to the procedure stored in the read-only memory (RoM) 16t), signals from the current location detection means 14 are received and sieved via the human output interface 16a, and the storage means 12 is controlled based on the result. CPU1 that performs processing such as displaying stored information on display means 10
6C, and a random access memory (ROM) 16d for temporarily storing captured data.

Particularly, in this invention, the above-mentioned II 111 means 16 stores data in the memory means 1 in response to the size of the GDOP from the GPS mentioned above.
The map is configured such that one map is selected from among a plurality of maps of two scales and displayed.

To explain an example of a method for determining the scale of a map, first, the scale of the displayed map is determined using the following calculation formula.

GDOPx20x103 Here, D is above &! It has a size that indicates the current position displayed on the display means 10, and usually has a diameter of about 4W.

In addition, in this example, GDOP II by GPS is divided into 10 stages as shown in Table 2 below, and the measurement am at each stage ranges from a maximum accuracy of 20 m to a minimum accuracy of 200 m.
Estimated settings have been made in stages. 20X in the above formula
103 is the value of this maximum 11 degrees.

Furthermore, the scale map is an integral multiple of 1/12,000 (
1/12,000, 1,150,000, 1/100,000, etc.) are prepared and stored in the storage means 12, so that the map of a scale larger than the SO calculated by the above formula is The smallest scale map among them is selected.

In other words, for example, when GDOPI is 9, if D is 4 shoes, it becomes 9x20X:103S-450004, so in this case, a scale map of 1.15 million is selected, and if the accuracy is good, a map with a large scale is selected. However, if the accuracy is poor, a map with a smaller scale is selected.

FIG. 4 shows details of the procedure for selecting a scale map using ill 10 means 16, in this example 1/1.2
5 maps with different scales from 50,000 to 1/200,000?
! , is biased. First, when the map scale determination routine starts at step (2), GPS reception by the current location detection means 12 is performed at step (2), the current location is detected according to the above-mentioned principle, and at the same time, the GDOPi
fl is also detected with ()l.

When GDOPla is detected, So is expressed by the above formula in step (2), and the obtained S is obtained. and minimum scale 11Q 12
A comparison with 50G is made in step ■, which is 125
If it is smaller than 00, step ■ is 1/1.2
The 50,000 scale map is displayed on the display means 10, and the process returns to the main route in step (2).

On the other hand, if So is determined to be larger than 12,500 in step ■, a comparison is made with the next scale value of 25,000 in step ■, and if SO is smaller than that scale value, then in step ■ After displaying the scaled map on the display means 10, step (2) is executed.

If it is determined in step ■ that 80 is greater than 25000, then a comparison (step [share], @) is made which scale value is smaller in order, and if SO is smaller than the scale value at each snap, Displaying the relevant scale map Return to Shunsui Tsubu■ after passing through step 00O.

(Effects of the Invention) As explained above in Example F, in the vehicle travel guidance device according to the present invention, the current location detection means (
Since the scale of the map to be displayed is selected and displayed in accordance with the current location detection means of GPS), it is possible to provide the user with information in the vicinity of the current location that corresponds to the accuracy, and the user can also At the same time, you can check the reception status of the VTR.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of the device of the present invention, Figure 2
J Overall diagram showing one embodiment of the equipment of the present invention, No. 3
The figure is an explanatory diagram showing the principle of GPS, and FIG. 4 is a flow chart diagram showing the procedure of the control means.

Claims (1)

[Claims] (1) Display means for displaying information for vehicle travel guidance, storage means for storing a plurality of maps of different scales, and positioning means for receiving radio waves from satellites and detecting the current position of the vehicle. a deterioration coefficient detection means for detecting a distance measurement error of the positioning means; and a deterioration coefficient detection means for detecting a distance measurement error of the positioning means; 1. A vehicle travel guidance device comprising a selection means for selecting a map, and a control means for displaying a map specified by the selection means on the display means.