JPH10135852A - Light beacon area detector for vics receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent mis-detection of a signal from a light beacon of a Vehicle Information and Communication System (VICS) receiver. SOLUTION: The VICS receiver is provided with a control section 7 that is mounted on a vehicle to receive vehicle information from a communication means of FM data multiplex broadcasting, a radio beacon and a light beacon so as to display any of data of FM data multiplex broadcasting, radio beacon and light beacon on a display device, a flag detector 8 that detects a frame synchronization flag of each frame of data received from the light beacon and consisting of a plurality of frames, and a light beacon area detection circuit 9 that detects the light beacon in an area receptacle by the VICS receiver by receiving prescribed data after the detection of the frame synchronization flag. In this case, while the light beacon area detection circuit 9 detects the reception area of the light beacon, when the flag detector 8 detects the frame synchronization flag, the control section 7 receives data of the light beacon through interruption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a receiver for a road traffic information communication system (VICS), and more particularly to an optical beacon area for preventing erroneous detection of a signal from an optical beacon, which is one of means for transmitting road traffic information. It relates to a detection device.

[0002]

2. Description of the Related Art In a VICS service, information provision using characters, information provision using simple figures, and information provision using a map are prepared as road traffic conditions. Means for transmitting road traffic information include FM data multiplex broadcasting, radio beacons, and optical beacons. In FM data multiplex broadcasting, the same information is provided to all vehicles in a certain broadcasting area. On the other hand, radio beacons and optical beacons installed on a large number of roads provide more detailed information than vehicles in the case of FM data multiplex broadcasting because the position of the vehicle is determined when the vehicle passes below it. . In particular, the information from the optical beacon is narrow area information of the area where the vehicle is currently traveling, and is very useful information for the driver.

[0003] In FM data multiplex broadcasting, information on a coverage area of a certain area is transmitted from a VICS center for a fixed time (for example, about 5 minutes). If the VICS receiver receives the information of the optical beacon during this time, the receiving process of the FM data multiplex broadcast is stopped, and the information of the optical beacon is preferentially received. In this case, the optical beacon uses a near-infrared light emitting diode as a light emitting element, and its receiving area is within a range of several meters before and after the optical beacon.

Then, information is transmitted from the optical beacon in a pulse amplitude modulation system at a communication speed of about 1 Mbit / sec. In a VICS receiver installed in a vehicle, information is received from any of FM data multiplex broadcasting, a radio wave beacon, and an optical beacon, and the received information is displayed on a navigation display screen.

[0005]

By the way, even in a VICS receiver, a near-infrared light receiving diode is used as a light receiving element for receiving information from an optical beacon. Since a light noise signal of sunlight, lighting equipment, and the like exists in areas other than the reception area of the optical beacon, the VICS receiver may erroneously detect the light noise signal as a transmission signal. Due to this erroneous detection, there is a problem that an interruption occurs during the reception of the FM data multiplex broadcast and the reception is disturbed as well as the reception of the radio beacon.

Accordingly, the present invention has been made in view of the above problems, and provides an optical beacon area detecting device of a VICS receiver capable of detecting a receiving area of an optical beacon and preventing erroneous detection in an area other than the receiving area.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a VICS receiver mounted on a vehicle for receiving road traffic information by means of FM data multiplex broadcasting, radio wave beacon and optical beacon communication means. Machine, the F
A control unit for displaying an image of any one of the data from the M-data multiplex broadcasting, the radio beacon and the optical beacon, and detecting a frame synchronization flag of each frame with respect to data of a plurality of frames received from the optical beacon; A flag detector, and an optical beacon area detection circuit for detecting an optical beacon in an area receivable with the VICS receiver by determining certain data after the detection of the frame synchronization flag; While the detection circuit is detecting the reception area of the optical beacon, and when the flag detector detects the frame synchronization flag, the control unit is caused to interruptly input the data of the optical beacon. Specifically, the optical beacon area detection circuit counts the number of bytes of the data of the road traffic information following the frame synchronization flag of the frame,
The reception area of the optical beacon is detected by latching the synchronization that separates the end of the data of the road traffic information section and determining the identity of the latched synchronization. The optical beacon area detection circuit counts the number of bytes of data following the frame synchronization flag of the frame, and latches a result of a cyclic redundancy check code (CRC) located at the rear of the road traffic information data. Then, the reception area of the optical beacon is detected by making a determination based on the result of the latched cyclic redundancy check code (CRC). By this means, it becomes possible to detect the reception area of the optical beacon inside and outside. And, outside the reception area of the optical beacon, the flag is not notified to the control unit as a frame synchronization flag as an interrupt, and the frame synchronization flag is notified to the control unit as an interruption only within the reception area of the optical beacon, so that erroneous detection is reduced. Interrupt processing time to the control unit is minimized. For this reason, the control unit can perform many processes such as the FM data multiplex broadcast and the radio wave beacon.

In addition, the optical beacon area detecting circuit includes a notifying section for notifying that the optical beacon receiving area has been detected when the optical beacon area detecting circuit detects the optical beacon receiving area. Specifically, the notification unit notifies by a beep sound,
Similarly, the notification is performed by turning on the light emitting diode, the notification is performed by blinking the light emitting diode, the notification is performed by voice synthesis, and the notification is performed by screen display. By this means, it is possible to notify the driver that there is an optical beacon reception area without erroneous detection.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic example of a vehicle-side receiver for receiving road traffic information from a VICS center according to the present invention. As shown in the figure, a VICS receiver is an FM antenna 1 for receiving FM data multiplex broadcasting and a radio beacon antenna 2 for receiving information from a radio beacon.
And an optical beacon detector 3 comprising a near infrared light receiving diode for receiving information from the optical beacon. To each of the FM antenna 1, the radio beacon antenna 2, and the optical beacon detector 3, demodulation circuits 4, 5, and 6 for extracting information as data are connected. A control unit (CPU) 7 that inputs the data extracted by the demodulation circuits 4, 5, and 6 processes the input data into display data and outputs it to a navigation display screen (not shown). Here, the navigation display screen is for drawing the obtained road information.

Further, the receiver receives the data extracted by the demodulation circuit 6 of the optical beacon detector 3 and detects a frame synchronization flag described later from the data. The logical product of the optical beacon area detecting circuit 9 for inputting the data extracted by the circuit 6 and detecting the optical beacon receiving area from the data and the output signals of the flag detecting circuit 8 and the optical beacon area detecting circuit 9 is obtained. A logical product (AND) circuit 11 that outputs an interrupt signal to notify the CPU 7 of the detection of the frame synchronization flag when the detection of the frame synchronization flag and the detection of the optical beacon receiving area occur simultaneously, and the optical beacon receiving area. And a notification unit 11 for notifying the user.

FIG. 2 is a diagram for explaining an optical beacon area signal formed by the optical beacon area detection circuit 9. As shown in this figure, if an optical beacon is installed in the traveling direction of the vehicle, a certain area before and after the optical beacon is set to be within the optical beacon area, and is distinguished from other optical beacon areas. . The optical beacon area detection circuit 9 outputs a high-signal optical beacon area signal when it is within the optical beacon area, and outputs a low-signal optical beacon area signal outside the optical beacon area.

FIG. 3 is a diagram for explaining an output signal of the AND circuit 10. As shown in this figure, when the optical beacon area signal from the optical beacon area detecting circuit 9 is a low signal, even if the flag detecting circuit 8 detects the frame synchronizing flag, the logical product circuit 10 sends the frame synchronizing flag to the CPU 7. When the detection is not notified and the optical beacon area signal is a high signal, the AND circuit 10 notifies the CPU 7 of the detection of the frame synchronization flag only when the flag detection circuit 8 detects the frame synchronization flag.

FIG. 4 is a diagram for explaining a schematic example of data transmitted from an optical beacon. As shown in this figure, a plurality of frames 1, 2,..., N, n + 1,
Are transmitted using the HDLC (High Level Data Link Control) procedure by the flag synchronization method. At the beginning and end of each frame, a 1-byte frame synchronization flag (7Eh) indicating a frame separation, 128 bytes of road traffic information after the first frame synchronization flag, and a 1-byte synchronization (AAh) indicating a separation of road traffic information ) Is composed of a 2-byte cyclic redundancy check code (CRC).

FIG. 5 shows the optical beacon area detection circuit 9 of FIG.
And a flag detection circuit 81 for inputting data extracted by the demodulation circuit 6 from the optical beacon detector 3 and a 129th byte counter 8 as shown in FIG.
2, a data latch 83, and a synchronization determination circuit 84 at a stage subsequent to the data latch 83. Here, the flag detection circuit 81 has the same configuration as the flag detection circuit 8.

After detecting the frame synchronization flag by the flag detection circuit 81, the 129th byte counter 82 extracts the clock signal used for the synchronous communication from the data, counts it, and is located after the road traffic information (128 bytes). 1
It counts until the 29th byte of synchronization (AAh), and outputs the output signal CLK to the data latch 83 after the count is completed. When the next frame synchronization flag comes within 128 bytes, the 129th byte counter 82 clears (CLR) the count of the 129th byte counter 82.

Further, the data latch 83 latches input data when there is an output signal CLK from the 129th byte counter 82. If the latched input data matches the synchronization (AAh), the synchronization determination circuit 84 determines (OK) that data has been received in the optical beacon area, and the logical product circuit 10
A high signal is output, but if they do not match, it is determined that the data outside the optical beacon area is erroneously detected (NG) and a low signal is output to the AND circuit 10 (see FIG. 4).

FIG. 6 shows the optical beacon area detection circuit 9 of FIG.
FIG. 9 is a diagram showing another example of the configuration. As shown in the figure, a different configuration is different from the 129th byte counter 82 in FIG.
An RC result position counter 85 and a CRC determination circuit 86 instead of the synchronization determination circuit 84 are provided. CR
After detecting the frame synchronization flag by the flag detection circuit 81, the C result position counter 85 extracts the clock signal used for the synchronous communication from the data and counts the same as described above, and performs the synchronization (AAh) of the 129th byte. C located after
RC, and after the count is completed, output signal CL
K is output to the data latch 83. When the next frame synchronization flag comes within 129 bytes, the count of the CRC result position counter 85 is cleared (CLR).

FIG. 7 is a diagram for explaining the relationship between data transmitted from an optical beacon and an optical beacon area signal. As shown in the figure, the CRC judgment circuit 83
If the result is OK, it is determined that data has been received in the optical beacon area, and a high signal is output to the AND circuit 10.
If so, it is determined that data is erroneously detected outside the optical beacon area, and a low signal is output to the AND circuit 10.

As described above, the optical beacon area detecting circuit of the present invention can detect whether or not the vehicle is in the optical beacon area. Since the interruption to the CPU 7 due to the optical beacon is minimized,
The processing time of M data multiplex broadcasting and the processing of radio beacons can be increased. FIG. 8 is a diagram illustrating an example of the notification unit 11 of FIG. As shown in FIG. 3A, the notification unit 11 may generate a beep sound. As shown in FIG. 4B, when the optical beacon area signal from the AND circuit 9 changes from a low signal to a high signal, the notification unit 11 emits a beep sound, and if the signal is within the optical beacon area, the driver does not perform the above-described erroneous detection. You can let them know. This sound allows the driver to immediately know that information has been obtained from the VICS optical beacon.

FIG. 9 is a diagram showing another example of the notification unit 11 of FIG. As shown in FIG. 2A, the notification unit 11 may be configured by a light emitting diode (LED). As shown in FIG. 3B, when the optical beacon area signal from the AND circuit 11 changes from a low signal to a high signal, the notification unit 11 turns on the LED, and notifies the driver that the signal is in the optical beacon area without the above-mentioned erroneous detection. be able to. This lighting allows the driver to immediately know that information has been obtained from the VICS optical beacon.

FIG. 10 is a diagram showing another example of the notification unit 11 of FIG. As shown in the drawing, when the optical beacon area signal from the AND circuit 10 changes from a low signal to a high signal, the notification unit 11 outputs.
Blinks the LED, and can notify the driver that the vehicle is within the optical beacon area without the erroneous detection. This blinking allows the driver to immediately know that information has been obtained from the VICS optical beacon.

FIG. 11 is a diagram showing another example of the notification unit 11 of FIG. As shown in FIG. 3A, the notification unit 11 may be configured by speech synthesis. As shown in FIG. 3B, when the optical beacon area signal changes from a low signal to a high signal from the AND circuit 10, the notifying unit 11 performs, for example, a voice message "entered the optical beacon area" and outputs a light message. The driver can be notified that the vehicle is within the beacon area without the above-mentioned erroneous detection. This blinking allows the driver to immediately know that information has been obtained from the VICS optical beacon.

FIG. 12 is a diagram showing another example of the notification unit 11 of FIG. As shown in FIG. 3A, the notification unit 11 may be configured by a screen display. When the optical beacon area signal from the AND circuit 10 changes from a low signal to a high signal as shown in FIG. 4B, the notification unit 11 displays, for example, "entered the optical beacon area" on the above-described navigation screen. The message can be displayed to the driver that the vehicle is in the optical beacon area without the erroneous detection.
This blinking allows the driver to immediately know that information has been obtained from the VICS optical beacon.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic example of a vehicle-side receiver for receiving road traffic information from a VICS center according to the present invention.

FIG. 2 is a diagram illustrating an optical beacon area signal formed by an optical beacon area detection circuit 9 of FIG.

FIG. 3 is a diagram illustrating an output signal of the AND circuit in FIG. 1;

FIG. 4 is a diagram illustrating a schematic example of data transmitted from an optical beacon.

FIG. 5 is a diagram illustrating a configuration example of an optical beacon area detection circuit 9 in FIG. 1;

FIG. 6 is a diagram showing another configuration example of the optical beacon area detection circuit 9 of FIG. 1;

FIG. 7 is a diagram illustrating a relationship between data transmitted from an optical beacon and an optical beacon area signal.

FIG. 8 is a diagram illustrating an example of a notification unit 11 of FIG. 1;

FIG. 9 is a diagram illustrating another example of the notification unit 11 of FIG. 1;

FIG. 10 is a diagram illustrating another example of the notification unit 11 of FIG. 9;

FIG. 11 is a diagram illustrating another example of the notification unit 11 of FIG. 1;

FIG. 12 is a diagram illustrating another example of the notification unit 11 of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... FM antenna 2 ... Radio beacon 3 ... Optical beacon detector 4, 5, 6 ... Demodulator 7 ... Control part 8 ... Flag detection circuit 9 ... Optical beacon area detection circuit 10 ... Logical product circuit 11 ... Notification part

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G08G 1/09

Claims (9)

[Claims] 1. A VICS receiver mounted on a vehicle for receiving road traffic information by a communication means of FM data multiplex broadcasting, radio beacon and optical beacon, comprising: A controller for displaying any one of the images as an image, a flag detector for detecting a frame synchronization flag of each frame with respect to the data of the plurality of frames received from the optical beacon, and a constant after the detection of the frame synchronization flag The VICS receiver and an optical beacon area detection circuit for detecting an optical beacon in a receivable area by determining the data of the VICS receiver. The optical beacon area detection circuit detects the reception area of the optical beacon. In the meantime and when the flag detector detects a frame synchronization flag. VIC, characterized in that to interrupt input data of the light beacon
Optical beacon area detection device for S receiver. 2. The optical beacon area detection circuit counts the number of bytes of data of the road traffic information following the frame synchronization flag of the frame, and latches synchronization that delimits the end of the data of the road traffic information section. The optical beacon area detection device for a VICS receiver according to claim 1, wherein the detection area of the optical beacon is detected by determining the latched synchronization identity. 3. The optical beacon area detection circuit counts the number of bytes of data following the frame synchronization flag of the frame, and latches a result of a cyclic redundancy check code located at the rear of the road traffic information data. 2. The optical beacon area detection device for a VICS receiver according to claim 1, wherein the detection area of the optical beacon is detected by making a determination based on the CRC result of the latched cyclic redundancy check code. 4. The apparatus according to claim 1, further comprising: a notifying unit for notifying that the reception area of the optical beacon has been detected when the optical beacon area detection circuit detects the reception area of the optical beacon. An optical beacon area detection device for a VICS receiver as described in the above. 5. The optical beacon area detecting device for a VICS receiver according to claim 4, wherein the notifying unit notifies by a beep sound. 6. The VIC according to claim 4, wherein the notifying unit notifies by notifying a light emitting diode.
Optical beacon area detection device for S receiver. 7. The VIC according to claim 4, wherein the notifying unit notifies by blinking a light emitting diode.
Optical beacon area detection device for S receiver. 8. The optical beacon area detection device for a VICS receiver according to claim 4, wherein said notification unit notifies by voice synthesis. 9. The optical beacon area detecting device for a VICS receiver according to claim 4, wherein said notifying unit notifies by a screen display.