JP2001255155A - Navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation apparatus which increases the possibility of selecting a station coming close to the apparatus and by which a chance to be selected is given to an FM multiplex broadcasting station moving away from the apparatus. SOLUTION: The navigation apparatus is provided with a GPS positioning means 24, which positions a present position. The apparatus is provided with a RAM 23, in which positional information on each transmitting station, is stored. The apparatus is provided with a control circuit 21, in which a transmitting station coming close to the apparatus and a transmitting station moving away from the apparatus are decides, on the basis of the output of the RAM 23 and on the basis of the position information stored in the RAM 23, which changes the weighting of a parameter corresponding to the transmitting stations, depending on whether the apparatus approaches or whether the apparatus moves away, and which decides the transmitting station to be selected on the basis of the weighted parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a VICS (Vehicle Information and Communicat) using FM multiplex broadcasting.
The present invention relates to a navigation device that receives various types of information, such as traffic congestion information of an ion system and multiplex information of FM teletext broadcasting.

[0002]

2. Description of the Related Art On April 23, 1996, a VICS service for transmitting traffic congestion information to a navigation device was started. This service information is performed by three communication means of FM multiplex broadcasting, a radio wave beacon, and an optical beacon.

[0003] As of December 21, 1999, there are 15 FM multiplex broadcasting stations, each transmitting different information. Since there are a plurality of FM multiplex broadcasting stations, the navigation device selects a broadcasting station to receive as the vehicle moves. The selection method includes a method of comparing reception levels based on electric field strength,
There is a method of comparing distances to FM multiplex broadcasting stations, and the like.
In addition, since it takes time to search for the electric field strengths of all the FM multiplex broadcasting stations, the FM multiplex broadcasting stations which can be currently received without searching without using the area information of the FM multiplex broadcasting stations stored in advance. And the extracted F
A method of searching only the M multiplex broadcasting station and examining the electric field strength (see Japanese Patent Application Laid-Open No. 9-270720) has been considered.

[0004]

However, according to the above-described method, the selection probability of the FM multiplex broadcasting station where the vehicle is moving away is the same as the selection probability of the FM multiplex broadcasting station which is approaching.

[0005] When an FM multiplex broadcasting station that is moving away is selected or determined as a candidate, there is a high possibility that the time during which the station stays in that area is short. If the staying time is short, change the receiving frequency to immediately move to the next FM multiplex broadcasting station
(Search) The number of times increases. It is not preferable to increase the number of searches because information cannot be received during the search. In addition, power consumption increases by driving the PLL circuit.

[0006] In particular, when an FM multiplex broadcasting station transmits information different from other FM multiplex broadcasting stations, such as VICS,
If an FM multiplex broadcasting station that is moving away is selected or determined as a candidate, it is likely to provide information that is not optimal for the user. For example, try to proceed 6
Without displaying the traffic congestion information of the FM multiplex broadcasting station on the 0km distance,
The traffic congestion information of the FM multiplex broadcasting station 50 Km left and slightly behind that does not proceed is displayed.

On the other hand, if FM multiplex broadcasting stations that are moving away are completely excluded from selection candidates, it is ignored that FM multiplex broadcasting stations that are moving away have little possibility of broadcasting optimal information. Become. For example, when an FM multiplex broadcasting station that is moving away is very close, it stays within the area of the FM multiplex broadcasting station for a long time, so that it is not bad to report information on the area. Also, the longer the driving time,
There is a high possibility that the direction of travel will change.

[0008]

SUMMARY OF THE INVENTION A navigation device according to the present invention has been made in view of the above points, and is a navigation device that selects and receives one or more of a plurality of transmitting stations for transmitting various service information. Positioning means for positioning the current position, storage means for storing position information of each transmitting station, and a transmitting station approaching the apparatus and moving away from the apparatus based on the output of the positioning means and the position information stored in the storing means. There is provided selecting means for determining a transmitting station, changing weights of parameters corresponding to the transmitting stations when approaching and moving away, and determining a transmitting station to be selected based on the weighted parameters.

The parameter is a receivable area, the parameter is a distance from a current position of the device to a transmitting station, and the parameter is a reception level.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. The navigation apparatus according to the present embodiment receives FM multiplex broadcasting and displays VICS information.

[0011] VICS information is transmitted by three communication means of FM multiplex broadcasting, radio wave beacon and optical beacon. F
M multiplex broadcasting is broadcast from NHK (Japan Broadcasting Corporation) facilities rented by the VISC Center, radio beacons are installed on expressways led by the Ministry of Construction, and optical beacons are general led by the National Police Agency other than expressways. Installed on the road. An FM receiver is required to display VICS information in FM multiplex broadcasting, a radio beacon receiver is required to display VICS information in a radio beacon, and an optical beacon is required to display VICS information in an optical beacon. A receiver is required. In this embodiment, VICS information is displayed by FM multiplex broadcasting, and has an FM receiver.

FIG. 1 is a block diagram showing the configuration of the main part of the first embodiment. This device comprises an FM receiver (FM tuner) (1) and a current position display (2).

In the FM receiver (1), an FM front end (11) amplifies a signal received from an antenna (12) to a high frequency signal, and converts the high frequency signal and an oscillation signal from a PLL circuit (13). It mixes and outputs an intermediate frequency signal. The FM-IF detector (14) performs FM on the intermediate frequency signal output from the FM front end (11).
Perform detection.

(15) is a multiplex signal detection circuit, which includes a multiplexing filter (not shown) and a data demodulation circuit (not shown).
Consists of The multiplexing filter is an FM-IF detector (1
The voice signal and the noise component are removed from the output signal of 4), and the multiplexed LMSK (Level Controlled Minimum Shift)
t Keying) Extract the signal. LMSK is a modulation method for controlling the size of a multiplex signal according to the size of a stereo audio signal. The data demodulation circuit demodulates the LMSK signal into a displayable data signal and sends it to the control circuit (16) of the FM receiver (1). The control circuit (16) of the FM receiver (1) instructs the frequency to be set in the PLL circuit (13).

In the current position indicator (2), (21)
Is a control circuit, which performs display based on a program written in the ROM (22). (23) is a RAM, which is information necessary for the operation of the control circuit (21), for example,
The area information of the FM multiplex broadcasting station is stored. (24) is G
PS (Global Positioning System) positioning means, which receives radio waves from GPS satellites, measures the current position, and transmits the measured data to the control circuit (2) of the current position display (2).
Output to 1). (25) is a map reproducing means, which reads map information from the DVD on which the map information is written and outputs it to the control circuit (21). (26) is a liquid crystal display unit which displays a map, a current position, and VICS information under the control of the control circuit (21). An input unit (27) performs various inputs related to the current position display and VICS.

The operation of the first embodiment will be described. FIG. 2 is a flowchart showing the main operation of the control circuit (21) of the current position display (2).

Area information is stored in the RAM (23) in advance. As shown in FIG. 3, the area information includes the frequency, position, and output of each FM multiplex broadcasting station.

In FIG. 2, the control circuit (21) of the current position display (2) detects whether or not it is necessary to switch the current reception frequency to the reception frequency of another FM multiplex broadcasting station by detecting a multiplex signal. The determination is made based on whether the multiplex signal has been detected by the circuit (15) (S1). FIG. 4 shows that the reception frequency is F1 (N
This is an example showing a state in which the apparatus is set to (AME1, FM multiplex broadcasting station at position P1), and the multiplex signal of the FM multiplex broadcasting station of NAME1 cannot be received due to movement of the apparatus. P1 to P4 indicate the positions of FM multiplex broadcasting stations. R1
R4 is a virtual radius proportional to the output of the FM multiplex broadcasting station, and circles of radii R1 to R4 centered on P1 to P4 are assumed to be the receivable virtual areas of the respective FM multiplex broadcasting stations. At this time, the current position of the vehicle is within the virtual area of the area E2, the area E3, and the area E4.

When the reception is disabled in FIG. 4, the control circuit (21) of the current position indicator (2) determines that it is necessary to switch the FM multiplex broadcasting station to another FM multiplex broadcasting station (S1). Y). First, the data of the current position and the traveling direction are represented by R
It is stored in the AM (23) (S2). The traveling direction is calculated based on the temporal change of the current position. And the approaching F
The radius of the virtual area of the M multiplex broadcasting station is increased, and the radius of the virtual area of the FM multiplex broadcasting station is reduced (S
3). Here, as shown in FIG. 5, if approaching, the virtual radius is increased by 20%, and if moving away, the virtual radius is increased by 2%.
Reduce by 0%. The determination as to whether or not approaching is based on whether or not the FM multiplex broadcasting station is ahead. Forward means that the angle between the vector from the current position to the FM multiplex broadcasting station and the vector in the traveling direction is ± 90 degrees or less. As shown in FIG. 6, in the state corrected in this way, the current position of the vehicle is within the virtual area of the area E2 ′ and the area E3 ′,
Area E4 'is outside the area. The control circuit (21) of the current position indicator (2) extracts FM multiplex broadcasting stations that are candidates for reception based on the virtual area thus corrected (S4). Here, F of area E2 'and area E3'
The M multiplex broadcasting stations (NAME2, NAME3) are extracted as candidates.

Next, a distance is calculated for the extracted FM multiplex broadcasting station (S5). Then, the distance to the approaching FM multiplex broadcasting station is shortened (Y in S6, S7). For example, as shown in FIG. 7, if approaching, the distance is reduced by 50%. Based on the corrected distance, the candidate FM multiplex broadcasting stations are arranged in ascending order (S8). Here, L3> L2 ×
0.5, the FM multiplex broadcasting station of NAME2 becomes the first place, and the FM multiplex broadcasting station of NAME3 becomes the second place.

In this order, the reception frequency is changed to check whether or not reception is possible, and the first FM multiplex broadcasting station determined to be receivable is set as a reception station (S9). FM first checked
There is a high possibility that the multiplex broadcasting station (here, the FM multiplex broadcasting station of NAME2) can receive, and the number of times of changing the reception frequency at this time is one. As described above, in the first embodiment, the change of the receiving frequency is small, and the transition of the FM multiplex broadcasting station can be performed in a short time.

In this way, the present invention corrects the evaluation of the FM multiplex broadcasting station selection based on whether or not the station is approached. This increases the possibility that a station that is approaching will be selected, stays in the area of the station for a long time, and reduces the number of times the reception frequency is changed. When the number of times the reception frequency is changed is reduced, power is saved, and the unreceivable time during the search is shortened.

In particular, when a station transmits information different from other stations such as VICS, it is highly likely that an approaching FM multiplex broadcasting station will be selected, so that optimal information is provided to the user. Probability is high.

[0024] In addition, it only lowers the evaluation of FM multiplex broadcasting stations that are going away, and does not exclude them from selection. For this reason, it is possible to give an opportunity to be selected to an FM multiplex broadcasting station that goes away. For example, when an FM multiplex broadcasting station that moves away is very close and is set as a receiving station regardless of the correction of the evaluation, it is highly likely that the FM multiplex broadcasting station will be in the area for a long time.

Next, a second embodiment will be described. The block diagram of the second embodiment is the same as FIG. 1 of the first embodiment. FIG. 8 is a flowchart showing the main operation of the control circuit (21) of the current position display (2) of the second embodiment. Steps 1 to 4 in FIG. 8 are the same operations as steps 1 to 4 in FIG. 1 which is the flowchart of the first embodiment, and a description thereof will be omitted.

In step S4, when the control circuit (21) of the current position indicator (2) extracts a station whose current position is within the area, it checks the reception level of the extracted FM multiplex broadcasting station (S21). And FM approaching
Highly evaluate the reception level of the multiplex broadcasting station (Y in S22,
S23). For example, as shown in FIG. 9, when approaching, the electric field strength is increased by 50%. The electric field strength is the highest based on the corrected electric field strength. The FM multiplex broadcasting station is set as a receiving station (S24).

In the second embodiment, as in the first embodiment, there is a high possibility that an approaching station will be selected. In addition, it is possible to give an opportunity to be selected without excluding FM multiplex broadcasting stations that go away from selection targets.

The second embodiment is more likely to increase the number of times the reception frequency is changed than the first embodiment, but can select a station with the best reception.

In the above-described embodiment, the correction of the evaluation based on the receivable area, the distance to the station, and whether or not the electric field strength approaches the station is performed. However, the present invention is applied to other selection elements. can do. In addition, the correction method may evaluate the selection element of the station approaching higher, evaluate the selection element of the station moving away lower, or perform both of them.

In the above-described embodiment, the traveling direction is calculated based on the change with time in the current position. However, the traveling direction may be detected by using a direction sensor based on geomagnetism or the like.

The station selection information in the above embodiment is FM
Although VICS information is based on multiplex broadcasting, the present invention provides VICS information based on beacons and RICS of the European Broadcasting Union.
The present invention can be applied to a system in which information is transmitted from a station such as a DS (Radio Data System).

[0032]

As described above, there is a high possibility that a station that is approaching will be selected, staying in the area of the station for a long time, and reducing the number of times of changing the reception frequency. When the number of times the reception frequency is changed is reduced, power is saved, and the unreceivable time during the search is shortened.

In particular, when a station transmits information different from other stations like VICS, it is highly likely that an approaching FM multiplex broadcasting station will be selected, so that optimal information is given to the user. Probability is high.

[0034] Further, only the evaluation of the FM multiplex broadcasting station that goes away is lowered, and it is not excluded from the selection. For this reason, it is possible to give an opportunity to be selected to an FM multiplex broadcasting station that goes away.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating main operations of the first embodiment.

FIG. 3 is a diagram showing an example of a selection element before correction of a receivable area.

FIG. 4 is a diagram showing FIG. 3 by coordinates.

FIG. 5 is a diagram illustrating an example of a selected element after a receivable area is corrected.

FIG. 6 is a diagram showing FIG. 5 by coordinates.

FIG. 7 is a diagram illustrating correction of a distance, which is an example of a selection element.

FIG. 8 is a flowchart showing a main operation of the second embodiment.

FIG. 9 is a diagram illustrating correction of an electric field intensity, which is an example of a selection element.

[Explanation of symbols]

 Reference Signs List 1 FM receiver 13 PLL circuit 15 Multiplex signal detection circuit 16 Control circuit (FM receiver) 2 Current position detector 21 Control circuit (Current position detector) 23 RAM 24 GPS positioning means 25 Map reproduction means 26 Display unit 27 Input unit

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinya Yoshida 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture F-term in Sanyo Electric Co., Ltd. 2F029 AA02 AB07 AC01 AC02 AC09 AC13 AC14 5H180 AA01 BB02 BB04 BB13 EE18 FF05 FF12 FF13 FF22 FF27 FF33 5K061 AA02 AA03 AA11 BB10 BB12 DD00 FF02 FF12 FF14 FF16 FF17 JJ06 JJ07 9A001 CC05 JJ10 JJ11 JJ78

Claims (4)

[Claims] 1. A navigation device for selecting and receiving at least one of a plurality of transmitting stations transmitting various service information, a positioning means for positioning a current position, and storing position information of each transmitting station. Based on the output of the positioning means and the position information stored in the storage means, determine the transmitting station approaching the apparatus and the transmitting station moving away, and correspond to those transmitting stations depending on whether approaching or moving away from the apparatus. A navigation unit comprising: a selection unit that changes a weight of a parameter to be transmitted and determines a transmission station to be selected based on the weighted parameter. 2. The navigation device according to claim 1, wherein the parameter is a receivable area. 3. The navigation device according to claim 1, wherein the parameter is a distance from a current position of the device to a transmitting station. 4. The navigation device according to claim 1, wherein the parameter is a reception level.