JPH02291098A - Navigation device - Google Patents

Abstract

PURPOSE:To correct the current position of a mobile body with high accuracy by setting position data as the current position with a detecting timing when detecting the direct underneath position of a road antenna after receiving the position data of the road antenna, correcting the data with a moving distance when receiving the position data after detecting the direct underneath position, and setting it as the current position. CONSTITUTION:The position arithmetic means and the current position correction means of a traveling vehicle are realized by a CPU 10, and the position data, etc., representing the direct underneath position of the road antenna 19 is transmitted with the road antenna 19. When the position data is received before detecting the direct underneath position of the antenna 19, the current position is displayed on a display part 6 at the inputting time of the CPU 10 by setting the direct underneath signal Su of the road antenna 19 as a trigger, and by correcting the deviation of the timing with a moving distance sensor, etc., when receiving the position data behind the direct underneath signal Su. In such a way, it is possible to correct the current position of the mobile body such as the traveling vehicle, etc., with high accuracy.

Description

[Detailed Description of the Invention] [Summary] The current position of the moving body is determined by a moving distance sensor and a direction sensor inside the moving body, and the current position of the moving body is determined by a distance sensor and a direction sensor inside the moving body. -1- When correcting the current position based on a traffic information source including position data, a navigation system that corrects the current position based on the timing of receiving a signal from the traffic information source and detecting directly below the roadside antenna. gation device, which connects moving objects and roads-1
−． Even if the communication area with the device is wide or the timing of receiving position data is delayed, the current position of the mobile object can be corrected with high accuracy.

[Industrial application field]

The present invention relates to a navigation device that corrects the current position of a moving object, such as a traveling vehicle, using absolute position data transmitted from a roadside device outside the moving object.

[Conventional technology]

FIG. 9 is a schematic diagram showing a conventional navigation device. Generally, in a navigation device, a travel distance sensor 7 such as a vehicle speed sensor and a direction sensor 8 such as a geomagnetic sensor are provided inside the vehicle as sensors for detecting data related to the current position of the vehicle. The travel distance sensor 7 detects the number of rotations of the wheels within a unit time of the traveling vehicle, that is, the traveling speed, and generates a number of vehicle speed pulses proportional to this traveling speed. Furthermore, the travel distance obtained by the counter 1.ci while traveling on these vehicle speed pulses is output as a travel distance data signal Sr. Further, the azimuth sensor 8 detects the azimuth of the vehicle relative to magnetic north and generates an azimuth data signal S. Output as .

These moving distance data signal Sr and azimuth data signal S
. are manually input into the current position calculation step 1. Note that this current position calculation means 16J. Usually, C of microcontroller etc.
The movement distance data signals M, S are realized by P U.
r and the orientation data signal S.

The current position of the vehicle is calculated by calculating the travel distance ^1] and the direction of the vehicle based on these and comparing them with the position at the start of travel that was previously input manually. Furthermore, navigation is performed by displaying the calculated current position on a map 10 of a display unit 6 such as a CRT using a cursor or the like.

The above-mentioned navigation system uses the travel distance sensor 7 and direction sensor 8 inside the vehicle without using any position information from the evening.
It is called an autonomous navigation system because it calculates and displays the current position by itself. In this self-contained navigation system, there is a possibility that a traveling error may occur due to the difference between the calculated current position and the actual current position, so heat condensers etc. are installed at regular intervals in each communication area with the traveling vehicle. It is necessary to obtain accurate position information from the on-road device 9.

For this reason, in the conventional LJ, traffic information is transmitted from the route-1 antenna 19 of the route-4-device 9 and includes location data indicating a specific position in the communication area, for example, a position directly below the roadside antenna 19. A traffic information receiving section 2 for receiving the information source S is provided inside the vehicle.

The details of this traffic information receiving section 2 will be described in the embodiment section. Furthermore, a current position correcting means 3 is provided for correcting the current position determined by autonomous navigation using the position data reproduced from the traffic information receiving section 2 as absolute position data. In this way, each time the vehicle enters the communication area with the road device 9, the traffic information receiving section 2 and the current position correcting means 3 can display the accurate current position on the map on the display section 6. can.

(Problems to be Solved by the Invention) As mentioned above, conventionally, absolute position data is received from the on-road device 9 as soon as the vehicle enters the communication area, and the position data is determined using autonomous navigation based on this position data. The current position was corrected and displayed on the display unit 6.

Generally, as the above-mentioned absolute position data, the traffic information source SL includes position data indicating the position directly below the road-1 antenna 19 installed at the center of the communication area. If the communication area is a narrow area of several meters, the current position is corrected at the time when the vehicle receives the above position data, assuming that the vehicle is traveling in the center of the communication area. However, the running error can be suppressed to within a few meters. However, when the communication area expands to several hundred meters, if the vehicle receives the above position data at the periphery of the communication area, the driving error will be several hundred meters, so the current position cannot be accurately determined. A problem arises in that it becomes difficult to correct properly. Furthermore, the traffic information source S also includes additional information that does not indicate the location of gas stations 1, etc.
In order to take in as much of this additional information as possible while driving, there is a trend toward a desire to widen the communication area.

The present invention was developed in view of the above problems, and even when the communication area between a moving object such as a traveling vehicle and a roadside device is wide,
``An object of the present invention is to provide a navigation device that can accurately correct the current position of a moving object.

[Means for Solving the Problems] FIG. 1 is a block diagram showing the principle configuration of the present invention. Note that the same reference numerals are used to denote the same components as those described above.

In FIG. 1, a road antenna position detection section 4 is provided that detects the position directly below the road antenna 19.

Then, if the position directly below the road antenna 19 is detected after receiving the position data of the road antenna 19, the current position correcting means 3 sets the position data received at the timing of detecting the position directly below the road antenna 19 as the current position. When the position data of the roadside antenna 19 is received after detecting directly below the antenna 19, this position data is corrected based on the moving distance after detecting directly below and set as the current position. As you said,
The current position correcting means 3 corrects the current position calculated within the moving body in accordance with the timing of receiving position data from the on-road device 9 and detecting directly below the on-road antenna.

[Function] In the navigation device of the present invention, the current position correcting means 3 determines the timing at which the position immediately below the road antenna is detected and the absolute position data reproduced from the traffic information source S, that is, the road antenna. Based on the timing of reception of the position data indicating the position immediately below -19, the current position calculated within the moving body is corrected with the position data from the on-road device 9.

Thus, according to the present invention, even if the communication area is wide or the timing of receiving position data is delayed, it is possible to accurately correct the current position of a moving object such as a traveling vehicle.

(Embodiment) Fig. 2 is a block diagram showing an embodiment of the present invention.Here, the current position calculation means 1 and the current position correction stage 3 inside a moving body, for example, a traveling car, are operated by a microcomputer or the like. CPU
This is realized by version 1.0. Further, as traffic information B S t from the outside of a moving object, for example, a running vehicle, the carrier is subjected to FSK modulation or PSK modulation and amplitude modulation according to various traffic information including position data indicating the position directly below the roadside antenna 19. The modulated wave obtained by performing this is transmitted from a roadside antenna 19 such as a split beam antenna. Furthermore, if two types of modulated waves whose amplitude modulation phases differ by 180 degrees from each other are transmitted bidirectionally from this roadside antenna 19 with the center directly below the roadside antenna 19, as shown in FIG. In the region (3) directly below the roadside antenna 19, the modulated waves cancel each other out, and the enhero preherence of the detected signal is effectively reduced. Furthermore, in the second session, the traffic information receiving unit 2 includes an RF amplifier 21 that selectively receives and amplifies the modulated wave, and a frequency converter that converts the frequency of the modulated wave to an intermediate frequency that is easy to amplify. 22, an IF amplifier 23 for re-amplifying the modulated wave output from this frequency converter, and an IF amplifier 2 for each.
and a position data detector 24 that detects and reproduces the position data from the output of No. 3. It should be noted that this position data detector 24 can also reproduce traffic information other than the position data described in "2". Furthermore, the road antenna position detection unit 4 includes an AM detector 41 that detects only the amplitude modulation component of the modulated wave output from the IF amplifier 23;
The AM detection signal S3 regenerated from the wave detector 4 is rectified, and the DC detection level is proportional to the average value of this AM detection signal Sa. The envelope pre-hell detector 42 outputs the above detection level ■. and a reference level VR, and an enable signal S for confirming that the vehicle has entered the communication area. A carrier detection unit 14 such as a diode detector that detects the presence or absence of a carrier.
It consists of In this carrier detection section 14, an IF amplifier 23 or an RF amplifier 21 (shown by a broken line in FIG. 2)
The modulated wave output from the converter is converted to TTL level. Here, if the vehicle passes sequentially through each area ■, ■, and ■ (Figure 3) of the communication area, the waveforms of the eight AM detection signals after AM detection in each area ■, ■, and ■ above are shown in Figure 4. become that way. In regions I and III, the signal waveform has a DC component superimposed on a sine wave component with a phase difference of 180° ((A), (B) in Figure 4).
)), in the area (2) directly below the roadside antenna 19, the sine wave components marked -J cancel each other out and become only the DC component with a low level ((C) in FIG. 4). Furthermore, detection level ■ after envelope level detection. As shown in FIG. 5, only the region (2) directly below the roadside antenna 19 is smaller than the reference level (2) ((C) in FIG. 5). therefore,
From the converter 50 shown in FIG.
h) A pulse-shaped signal Su directly below the roadside antenna such that
is output. On the other hand, carrier level antenna 1
9, the enable signal S8 output from the carrier detection section 4 becomes "H" while the vehicle is passing through the communication area, so the AND means 15
A signal Su directly below the roadside antenna is manually input to the CPU 10 as a trigger. Note that the logical product means 15 can also be realized by a CPU 1.0.

In general, position data indicating directly below the roadside antenna 19 is
It is serially transmitted from the roadside antenna 19 in frames of several heights together with other traffic information. therefore,
In order for the traffic information receiving section 2 to receive the traffic information aSt in frame units, a predetermined reception time T is required. Furthermore, -J is reproduced from the traffic information receiving unit 2.
- A predetermined processing time T2 is required for the CPU 10 to process the position data in units of frames. In other words, this reception is completed after a time T,+T2 has elapsed since the traffic information receiving section 2 started receiving the position data. As a result, the following two cases occur regarding the relationship between the timing of completion of reception of the position data and the timing of detecting the area directly below the road antenna 19 and inputting the signal S II directly below the road antenna to the CIIU 10. The first case, as shown in FIG. 6, is a case in which the reception of the position data is completed before detecting the position directly below the roadside antenna 19.

On the other hand, the second case, as shown in FIG. 7, is a case in which the reception of position data is completed after detecting the location directly below the roadside antenna 19, and for example, a communication error occurs immediately after entering the communication area. This corresponds to a case where the start of receiving position data is delayed.

In the first case above, the path-1-directly below the antenna {
At the time input to the CPU 10, the No. g S1 is used as the 1-trigger (hereinafter abbreviated as the "direct trigger") to move the current position on the map "2" on the display section 6 to the position directly below the roadside antenna specified by the position data. It may be displayed by moving with cursor C. However, in the second game, since reception of the position data has not yet been completed at the time when the direct trigger is input, the movement distance sensor 7 etc. detects the difference between the timing of the direct trigger manual input and the timing of completion of position data reception. must be corrected to display the current position. Next, the procedure for processing the above two cases by the CPU 10 such as a microcomputer will be described in detail.

Figures 8A, 8B, and 8C are flowcharts for explaining the procedure for correcting the current position of a traveling vehicle in an embodiment of the present invention, and Figure 8A is the procedure for displaying the current position by self-contained navigation. FIG. 8B is a flowchart for explaining the processing procedure after position data is received, and FIG. 8C is a flowchart for explaining the processing procedure after inputting the direct I/Riga.

In FIG. 8A, the current position is calculated by the CPU 10 using the travel distance {7 and the orientation sensor 8 in the vehicle (step a), and is displayed on the map of the display unit 6 with a cursor C. CPII 10 with so-called autonomous navigation
This shows the processing flow. This processing flow is C
It runs constantly unless the PU 10 receives location data.

In FIG. 8B, after the vehicle enters the communication area, the traffic information receiving unit 2 receives position data.
When an interrupt signal is input to (step C), the above CP
U 10 immediately begins receiving location data (step d). If the CPU 10 completes receiving the position data within a certain period of time (step e, step [
), CP assuming that accurate location data has been received.
The U 10 enters the state of waiting for input of the immediate trigger (step g).

In Fig. 8C, when the above-mentioned immediate 1/rega is input (step h), if the reception of position data has already been completed as in the above-mentioned first case (Fig. 6), (step i ), -1 Correct and display the current position of the map-hi on the display unit 6 by setting the position directly below the roadside antenna 19 specified by the position data as the accurate current position (step j)
. On the other hand... As in the second case (Fig. 7) above, if the reception of the position data is not completed (step i
), from the time when the direct 1 trigger is input, the moving distance sensor 2 in the running vehicle, for example, the vehicle speed sensor, starts counting vehicle speed pulses (step 1 (). Then, again in FIG. 8B, the reception of position data is started. At the same time as the calculation is completed (step e, step g), the counting of vehicle speed pulses is stopped (step r), and the distance corresponding to the count 1 to number of the vehicle speed pulses is immediately below the road-L antenna 19 specified by the position data. Correct the current position by adding it to the position of (
Stethop m). This corrected current position is displayed on the display unit 6 as in the first case (step j in Fig. 8C).

In the second embodiment (FIG. 2), even if the timing of receiving position data from the roadside antenna 19 outside the vehicle is delayed, the position data is corrected using the existing travel distance sensor, etc. Accurate current position can be displayed without providing extra correction means.

In addition to the above-mentioned embodiments, the road antenna position detecting unit 4 may also include, for example, an antenna with a very narrow transmission area for detecting the position of the road antenna, in addition to the antenna 19 for transmitting position data. good.

[Effects of the Invention] As explained above, according to the present invention, the current position of the moving object can be corrected with high precision even when the communication area between the moving object and the road device is wide or even when the timing of receiving position data is delayed. A navigation device capable of doing the following is realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic structure of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing the relationship between the communication area and the enherobe level. Figure 4 is a diagram showing the waveform after AM detection in each part of the communication area, Figure 5 is a diagram showing the waveform after envelope vibration detection in each part of the communication area, and Figure 6 is a diagram showing position data reception before detection directly under the roadside antenna. Figure 7 is a diagram showing the timing relationship when position data reception is completed after detection directly below the roadside antenna. Figure 8A is the procedure for displaying the current position using self-contained navigation. Flowchart 1 to explain
・, FIG. 8B is a flowchart for explaining the processing procedure after receiving position data, FIG. 8C is a flowchart 1 for explaining the processing procedure after inputting the direct trigger, and FIG. 9 is a flowchart for explaining the processing procedure after receiving the position data. FIG. In the figure, 1... Current position calculating means, 2... Traffic information receiving section, 3... Current position correcting means, 4... Road antenna position detecting section,

Claims (1)

[Claims] 1. A current position calculation means (1) that calculates the current position of the mobile body using a moving distance sensor (7) and a direction sensor (8) within the mobile body; and a roadside antenna (19) of a roadside device (9) having a predetermined communication area. ), the traffic information receiving unit (2) receives a traffic information source (St) that is transmitted from the roadside antenna (19) and includes at least position data of the roadside antenna (19);
a current position correction means (3) for correcting the calculated current position based on the position data reproduced from 2); and a road antenna position detection unit (4) for detecting a position directly below the road antenna (19). In the navigation device comprising: the current position correcting means (3), the road antenna (1);
After receiving the position data of 9), the road antenna (19)
If the position directly below is detected, the received position data is set as the current position at the timing when the position directly below is detected, and after the position directly below the road antenna (19) is detected, the position data of the road antenna (19) is received. In the case where the position data is detected directly below, the navigation device corrects the position data based on the distance traveled after detecting the position immediately below to determine the current position.