JPH05327577A - Information communication equipment for vehicle - Google Patents

Abstract

PURPOSE:To accurately receive optimum information corresponding to a road classification by providing a discrimination information transmitter, which has a very narrow reception area, in the vicinity of the entrance/exit of the road and receiving data in accordance with discrimination information from this transmitter. CONSTITUTION:When an automobile 4 on which a receiver 1 is mounted passes an entrance tollhouse 5 and joins to a toll road, a flag indicating running on the toll road is set in the memory in the receiver 1 by discrimination information from a discrimination information transmitter TX1 provided in the vicinity of the tollhouse 5. While this flag is set, data from running information transmitters TX3 and TX4 provided on a main line 8 are received to display snarl information, branch line guide information, or the like on a display device. When the automobile 4 passes an exit tollhouse 13 and goes to a general road 15, the flag is reset, and consequently, data from transmitters TX3 and TX4 are not erroneously received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle used for position correction in a so-called navigation device for displaying a map screen and the position of the vehicle on a display device mounted on a vehicle, and for displaying a traffic jam condition. Information communication device.

[0002]

2. Description of the Related Art In recent years, in automobiles, a navigation device has been put into practical use, which displays the traveling direction and traveling speed of the vehicle on a map screen and is used for determining the traveling route of a driver. In this navigation device, position correction is performed based on position data from a transmitter provided adjacent to a road, or a signal indicating road information or a signal for guiding a branch road is received from the transmitter. Has proposed a configuration for displaying traffic jam information, guidance information for a branch road, and the like.

However, such information does not cause a great difference in electric field strength level between when it is received on a highway and when it is received on a general road. Therefore, for example, when the information is for a highway and a general road runs in parallel on the highway, the traffic congestion information and the branch road guidance information are also received by the vehicle traveling on the general road. This can lead to confusion. And vice versa,
There is also a risk that information for general roads may be received by vehicles on the highway. The problem is that the information for the highway is received on the ordinary road rather than the information for the highway is received on the elevated road and on the highway shielded by metal noise barriers. When it is done, it is remarkable.

[0004]

In order to solve the above problems, it is conceivable to provide a so-called squelch circuit in the receiver, for example. However, the squelch circuit is for muting an extremely weak signal of a distant transmitting station, and when the level difference between the electric field strength levels is relatively small as described above, the information to be received and the information to be received should not be received. It cannot be distinguished from information exactly.

An object of the present invention is to provide an information communication device for a vehicle which can accurately display only the traveling information to be received.

[0006]

According to the present invention, a traveling information transmitter adjacent to a road transmits traveling information about traveling of a vehicle, and a receiver mounted on the vehicle receives and displays the traveling information. In an information communication device of a vehicle, an identification information transmitter having a very small reception area is provided near an entrance to a road of a predetermined type, and an entrance or an exit to the road of the predetermined type is provided from the identification information transmitter. Is transmitted to the receiver, and the receiver selectively displays the traveling information in response to the received identification information.

Further, the present invention is a vehicle information communication apparatus, wherein traveling information relating to traveling of a vehicle is transmitted from a traveling information transmitter adjacent to a road, and the receiver mounted on the vehicle receives and displays the information. In the receiver, the receiver detects a receiving electric field strength of the traveling information, a holding means that receives a detection result of the detecting means and holds a peak value of the received electric field strength, and a predetermined type of road traveling. A value smaller than the peak value of the received electric field intensity to be detected at a certain time by a predetermined level is used as a discrimination level, and only the information from the transmitter whose peak value held by the holding means is equal to or higher than the discrimination level is displayed. An information communication device for a vehicle, comprising: a level discrimination means.

[0008]

According to the present invention, it is possible to drive a vehicle such as traffic jam information or branch road guidance information from a traveling information transmitter provided adjacent to a road to a road of a predetermined type such as an expressway or a motorway. When transmitting the traveling information and receiving it by a receiver mounted on the vehicle to display the information, there is an extremely small reception area of about several meters near the entrance to the road of the predetermined type, for example, near the toll gate. Provide an identification information transmitter. From the identification information transmitter, identification information indicating that the road is an entrance or an exit to the road of the predetermined type is transmitted.

The receiver which has received this identification information sets a flag indicating that it is an expressway, for example, after passing through the entrance, and receives the traveling information while the flag is set. And display it. When the traveling of the road of the predetermined type is completed and the vehicle passes the exit, the receiver resets the flag and receives the traveling information on the general road. In this way, only the optimum information corresponding to the road type can be accurately selected and received.

Further, according to the present invention, when receiving the traveling information, a detecting means, a holding means, and a level discriminating means are provided. The detection means detects the received electric field strength of the traveling information from the traveling information transmitter and gives the detection result to the holding means. The holding means realized by a peak hold circuit holds the peak value of the received electric field strength and gives it to the level discriminating means.

In the level discriminating means, from the peak value of the received electric field intensity to be detected when the vehicle travels on a predetermined type of road such as an expressway or an automobile exclusive road in advance,
A value smaller by a predetermined level is set as the discrimination level. The level discrimination means displays only the information of the roadside transmitters whose peak value held by the holding means is equal to or higher than the discrimination level. Therefore, only information that should be received on an expressway with a relatively high electric field strength is displayed, and on an ordinary road running parallel to the expressway under the expressway, the information for the expressway is displayed. It is possible to reliably prevent erroneous reception.

[0012]

1 is a block diagram showing an electrical configuration of a receiver 1 according to an embodiment of the present invention, FIG. 2 is a plan view showing the vicinity of an interchange 3 of an expressway 2, and FIG. It is a perspective view which shows information transmitter TX1 and TX2. Car 4
Can be joined from the entrance toll gate 5 through the introduction paths 6 and 7 to the up line 9 or the down line 10 of the main line 8, respectively. Similarly, the automobile 4 traveling on the up line 9 and the down line 10 of the main line 8 can join the general toll 15 from the exit toll gate 13 through the introduction routes 11 and 12, respectively.

An identification information transmitter TX is provided near the entrance toll gate 5.
1 is arranged, and an identification information transmitter TX2 is arranged near the exit toll gate 13. The outputs of the identification information transmitters TX1 and TX2 are, for example, about several mW, and transmit identification signals at a high carrier frequency of 2.5 GHz, for example. Therefore, the arrival area of the identification signal, that is, the receivable range is indicated by reference numeral A in FIG.
As shown by, the radius is extremely small, for example, within a radius of several meters. Further, the automobile 4 at least slowly moves through the toll booths 5 and 13. This allows toll booths 5 and 1
The receiver 1 mounted on the automobile 4 that has passed 3 can identify whether the vehicle 1 has entered the highway 2 or has exited the highway 2.

Further, traveling information transmitters TX3 and TX4 are arranged in the vicinity of the main line 8, for example, at road shoulders. From the traveling information transmitters TX3 and TX4, position information for navigation and information such as a traffic jam condition are transmitted following identification information indicating that the information is for the highway 2.

The information from the transmitters TX1 to TX4 is
The signal is received by the antenna 21 of the receiver 1 and restored by the receiving circuit 22 into digital data. In the receiving circuit 22, the received signal is given from the antenna 21 to the mixing circuit 32 via the high frequency amplifying circuit 31, and the local oscillating circuit 3
The intermediate frequency signal thus mixed with the local oscillation signal from 3 is input to the intermediate frequency amplification circuit 35 via the band pass filter 34. The output from the intermediate frequency amplifying circuit 35 is demodulated into a digital signal by the data demodulating circuit 36 and then given to one input of the AND gate 37.

The intermediate frequency signal from the intermediate frequency amplifier circuit 35 is also input to the carrier detection circuit 38,
As shown in FIG. 4, a DC voltage corresponding to the received electric field strength level is output from the carrier detection circuit 38 and input to the non-inverting input terminal of the comparator 40 via the line 39. The reference voltage V3 generated by dividing the high level voltage + B by the variable resistor 41 is input to the inverting input terminal of the comparator 40. The comparator 40 derives a high level output to the other input of the AND gate 37 when the voltage of the line 39 is equal to or higher than the reference voltage V3.

Therefore, the AND gate 37 outputs demodulated data during a period in which the received electric field strength is equal to or higher than a predetermined level corresponding to the reference voltage V3, and the demodulated data is sent to the communication control circuit 42. In addition to being input, the clock signal is input to the clock reproduction circuit 43 to reproduce the clock signal and input to the communication control circuit 42.
The communication control circuit 42 supplies the demodulated data and clock signal to the processing circuit 23 realized by a microcomputer or the like.

A memory 24 is provided in association with the processing circuit 23. The processing circuit 23 includes an identification information transmitter TX.
A flag indicating whether or not the vehicle is traveling on a highway is set or reset in the memory 24 in accordance with the identification information from the vehicle 1, TX2, and the traveling information transmitter is set during the period when the flag is set. Based on the information transmitted from TX3 and TX4, the position information and the traffic jam information are decoded and given to the image composition circuit 26 via the display buffer 25.

The image synthesizing circuit 26 responds to a selection operation from the input device 27 realized by a so-called touch switch or key switch, and on the map screen created based on the map information read from the CD-ROM decoder 28. An image in which the position of the own vehicle is synthesized is created and displayed by the display device 29 realized by a cathode ray tube or a liquid crystal display device. At this time, according to the contents stored in the display buffer 25,
The image synthesizing circuit 26 corrects the position of the own vehicle and displays the traffic congestion information on a synthesizing screen of characters and maps.

FIG. 5 is a flow chart for explaining the display operation of the traveling information as described above. Step n1
Then, initialization processing such as resetting of the memory 24 is performed. In step n2, the frame synchronization of the received data is detected, and when the frame synchronization is obtained, step n
Move to 3. In step n3, the received data is stored in the memory 24. In step n4, it is judged whether or not the data reception is completed. If not, the process returns to step n3 to complete the data reception. Move to step n5.

When the information from the transmitters TX1 to TX4 is received in this way, in step n5, it is determined whether or not the information is identification information indicating entry / exit to / from an expressway, that is, from the identification information transmitters TX1 and TX2. If it is, the flag F1 indicating whether or not the vehicle is traveling on an expressway is rewritten in step n6, and then the process proceeds to step n7. Move on to.

In step n7, it is judged whether or not the identification information indicating the road type in the received data and the flag F1 match, and if so, in step n8, the reading of subsequent information data is performed. After the display image has been generated and the display image has been created, the process returns to step n1. If not, the reception information is not captured and the process directly returns to step n1.

As a result, only the information necessary for traveling on the highway 2 is accurately displayed without erroneously recognizing the information from the traveling information transmitters TX5, TX6 provided on the parallel road 15 running in parallel. can do.

In the above-described embodiment, the same identification information is transmitted from the identification information transmitters TX1 and TX2, and therefore the processing circuit 23 travels on the highway every time the identification information is received. Although the flag F1 indicating whether or not it is in the middle is set or reset, as another embodiment of the present invention, different identification information is transmitted from the identification information transmitters TX1 and TX2, which causes the processing circuit 23 to operate. It may be possible to identify whether the vehicle has entered the highway 2 or left.

Further, the memory 24 is composed of a non-volatile memory capable of retaining the stored contents even when the power supply is stopped, or backup power is supplied to the memory 24 even when the ignition key switch is turned off. The stored contents can be retained. As a result, even if the ignition key switch is once turned off in a service area such as a highway, it does not affect the subsequent operation of receiving the traveling information.

FIG. 6 is a block diagram showing the electrical construction of a receiver 51 according to another embodiment of the present invention. This embodiment is similar to the above-mentioned embodiment, and the same reference numerals are given to corresponding parts. Attach. In this embodiment, the output from the carrier detection circuit 38 is also input to the peak hold circuit 52.

FIG. 7 is an electric circuit diagram showing a specific structure of the peak hold circuit 52. The peak hold circuit 52 includes two buffers 61 and 62 and a capacitor 63.
And a diode 64 and a switch 65. The output from the carrier detection circuit 38 is input to the non-inverting input terminal of the buffer 61, and the output from the output terminal of the buffer 61 is given to the capacitor 63 via the diode 64 and charged. The terminal voltage of the capacitor 63 is fed back to the inverting input terminal of the buffer 61. The terminal voltage of the capacitor 63 is input to the non-inverting input terminal of the buffer 62, and the output from the output terminal of the buffer 62 is led to the comparator 53 and fed back to the inverting input terminal of the buffer 62. Has been done. A switch 65 is provided in parallel with the capacitor 63.
Is controlled by the communication control circuit 42 as will be described later.

The hold value of the peak hold circuit 52 is applied to the non-inverting input terminal of the comparator 53, and the high level voltage + B applied to the inverting input terminal is divided by the variable resistor 54 to be the reference voltage V1 or more. , The comparator 53 outputs a high level output to the communication control circuit 42.

The reference voltage V1 is set higher than the reference voltage V3, and the communication control circuit 42 has the output from the comparator 53 at the high level and is measured by the timer 55 as described later. Predetermined time W
The data input through the AND gate 37 is given to the processing circuit 23 within 1 or less. When the output from the comparator 53 becomes low level and after the timer 55 measures the predetermined time W1, the communication control circuit 42 outputs a reset signal to the line 56, and the capacitor of the peak hold circuit 52 is output. The charge of 63 is discharged and reset.

By the way, the input level Pr of the receiver can be expressed by Equation 1.

[0031]

[Equation 1] Pr = {λ / (4πd)} ² · Pt · gti · gri [W] where Pt is the transmission power, gti is the gain of the transmitting antenna, and gri is the gain of the receiving antenna. λ
Is the wavelength and d is the distance between the transmitting and receiving antennas.

Here, as shown in FIG. 8, let us consider a case where the highway 2 is constructed on the general road 15 by an overpass. The road surface height L1 from the ground of the highway 2 is set to 5 m,
The height L2 of the antenna 20 of the traveling information transmitters TX3, TX4 from the road surface of the highway 2 is 5 m. In the case of the configuration shown in FIG. 8, the traveling information transmitters TX3, TX4
The receiver input level Pr on the highway 2 immediately below the antenna is, for example, -35 dBm. On the other hand, the input level on the general road 15 directly below the antenna is about 6 dB lower than on the highway 2 by -41 dB.
It will be about m. It should be noted that the highway 2 is provided with a shielding member such as a metal soundproof wall, and therefore, in reality,
The ordinary road 15 has an attenuation of 6 dB or more as compared with that on the highway 2.

That is, the electric field strength change when the automobile 4 travels on the highway 2 and the general road 15 is as shown in FIG. In FIG. 9, reference numeral α1 is a traveling value of the highway 2, and reference numeral α2 is a traveling value of the general road 15. In FIG. 9, the level P3 is a value for setting the length of the communication area A1 on the highway 2, and is, for example, −50 dBm. The length of the communication area A1 at this time is about 70 m. Also, level P2
Indicates the peak value of the electric field strength when traveling on the general road 15, and the level P0 is the peak value when traveling on the highway 2. The reference voltage V3 to the comparator 40 is a DC voltage corresponding to the level P3, and the comparator 53
The reference voltage V1 of at least the level P2 or higher,
For example, it is set to a value corresponding to -38 dBm.

Therefore, when the automobile 4 travels on the highway 2 in the direction of arrow B in FIG. 9, the reception of the traveling information is started from the position B0 where the receiver input level becomes the peak value P0, and the input level is reached. Is the position B at which the level P1 is reached.
Received up to 1. The communication control circuit 42 discharges the peak hold circuit 52 when the input level does not reach the level P1 or more even after the receiver input level reaches the level P3 or more and a predetermined time W1 or more elapses. To reset. The time W1 is selected as a time at which the peak value P0 should be detected as the receiver input level becomes equal to or higher than the level P3 and then rises as the vehicle 4 travels. In this way, general road 1
It is possible to prevent malfunction when the receiver input level from the traveling information transmitters TX5 and TX6 of No. 5 locally rises on the highway 2.

FIG. 10 is a flow chart for explaining the data receiving operation as described above. When the receiver input level becomes equal to or higher than the level P3 and a high level output is derived from the comparator 40 and the gate of the AND gate 37 is opened, the process proceeds to step m1 to reset the memory 24 and the timer 55. Initialization processing such as start of counting is performed. In step m2, the frame synchronization of the received data is detected, and when the frame synchronization is obtained, the process proceeds to step m3. In step m3, the received data is stored in the memory 24. In step m4, it is judged whether or not the data reception is completed. If not, the process returns to step m3 to complete the data reception. Move to step m5.

At step m5, it is judged if the output of the comparator 53 is at a high level, that is, if the input level of the receiver is not less than the level P1. If not, at step m6, the timer 55 is operated. From the count value, it is determined whether or not the time W1 has elapsed since the start of this data reception. If not, the process returns to step m5, and if so, in step m9,
The communication control circuit 42 conducts the switch 65 to discharge the electric charge of the capacitor 63, and then the transmitter to be received, for example, a transmitter other than TX3, TX4, that is, TX5, TX6.
It is judged that the data is from the above, and the process returns to the step m1.

When the output of the comparator 53 is at the high level in step m5, the communication control circuit 42 conducts the switch 65 to make the capacitor 63 in step m7.
Is discharged. At step m8, the video signal is given to the image synthesizing circuit 26 via the display buffer 25,
After the image is displayed, the process returns to step m1.

Also in this way, the traveling information to be received only on the highway 2 or the general road 15 can be accurately received.

The display may be an image display using a liquid crystal display device or a cathode ray tube as described above, or may be performed by synthesizing the received traveling information data with voice.

[0040]

As described above, according to the present invention, a vehicle such as traffic congestion information or branch road guidance information from a traveling information transmitter provided adjacent to a predetermined type of road such as a highway or a motorway. In receiving the traveling information about the traveling of, the identification information transmitter having a very small reception area is provided near the entrance to the road of the predetermined type, and the receiver corresponds to the identification information from this transmitter. Since the traveling information is selected and received, only the optimum information corresponding to the type of road can be accurately received.

Further, according to the present invention, when the traveling information is received, the received electric field strength of the traveling information is detected, and the peak value of the detection result is usually detected during traveling on the road of the predetermined type. A predetermined level, for example, a value smaller by 3 dB from the peak value of the received electric field strength to be, for example, -41 dB, is used as the discrimination level,
When it is above the discrimination level, the traveling information is displayed. In this way, only the information corresponding to the road on which the vehicle is traveling can be accurately displayed, and the driver is not confused.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a receiver 1 according to an embodiment of the present invention.

FIG. 2 is a plan view showing the vicinity of an interchange 3 of a highway 2.

FIG. 3 is an identification information transmitter T provided at toll gates 5 and 13.
It is a perspective view of X1, TX2.

FIG. 4 is a graph showing characteristics of a carrier detection circuit 38.

FIG. 5 is a flowchart for explaining the operation of the receiver 1.

FIG. 6 is a block diagram showing an electrical configuration of a receiver 51 according to another embodiment of the present invention.

FIG. 7 is an electric circuit diagram showing a specific configuration of a peak hold circuit 52.

FIG. 8 is a cross-sectional view schematically showing a parallel highway 2 and a general road 15.

9 is a graph showing a change in a receiver input level when the automobile 4 is running in the state shown in FIG.

FIG. 10 is a flowchart for explaining the operation of the receiver 51.

[Explanation of symbols]

 1,51 Receiver 2 Expressway 3 Interchange 4 Automobile 5,13 Tollgate 15 General road 21 Antenna 22 Reception circuit 23 Processing circuit 24 Memory 26 Image synthesis circuit 29 Display device 36 Data demodulation circuit 38 Carrier detection circuit 40,53 Comparison 42 Communication control circuit 52 Peak hold circuit 55 Timer

Claims (2)

[Claims] 1. An information communication device for a vehicle, wherein traveling information regarding traveling of a vehicle is transmitted from a traveling information transmitter adjacent to a road, and a receiver mounted on the vehicle receives and displays the information. An identification information transmitter having an extremely small reception area is provided near the entrance to the road of the specified type, and identification information indicating that the identification information transmitter is an entrance or an exit to the road of the predetermined type is provided. The information communication device for a vehicle, wherein the receiver selectively displays the traveling information in correspondence with the received identification information. 2. An information communication device for a vehicle, wherein traveling information regarding traveling of a vehicle is transmitted from a traveling information transmitter adjacent to a road, and the receiver mounted on the vehicle receives and displays the information. The receiver includes a detection unit that detects the received electric field strength of the traveling information, a holding unit that receives the detection result of the detection unit, and holds a peak value of the received electric field strength, and a detection unit that is used when traveling on a predetermined type A level discriminating means for displaying only information from the transmitter whose peak value held by the holding means is equal to or higher than the discriminating level, with a discriminant level being a value smaller than the peak value of the received electric field intensity to be discriminated. An information communication device for a vehicle, comprising: