JP2001319293A - Optical beacon on-vehicle unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a rainfall state by utilizing an optical beacon on-vehicle unit. SOLUTION: The optical beacon on-vehicle unit 1 arranged in the neighborhood of the windshield FG of a vehicle is provided with a light emitting part 11 for emitting a transmission data IR signal, a light emitting driver 12 for controlling the part 11, a light receiving part 13 for receiving the IR signals of various kinds of data, a reception amplifier 14 for amplifying and demodulating the received IR signals, a signal processing part 15 for Manchester- encoding transmission data and decoding it from a Manchester code, a CPU 16 for processing various kinds of data, a memory 17 for storing data, an A/D converting part 18 for converting a light receiving amount into a digital value and a judging part 19 for judging a rainfall state. The CPU 16 periodically outputs a rainfall detecting signal for detecting the rainfall state from the light emitting part 11 unless a traffic information communication processing is performed, the light receiving amount obtained by reflection against the windshield FG where raindrops RN are attached is converted into the digital value by the A/ D converting part 18 and the judging part 19 detects the rainfall state by comparison with a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-board optical beacon device installed near a windshield in a vehicle and communicating traffic information with an optical beacon road device installed on a road on which the vehicle runs. In particular, the present invention relates to a vehicle-mounted optical beacon device capable of detecting a rainfall state without requiring dedicated hardware.

[0002]

2. Description of the Related Art At present, various kinds of information such as current position and destination information, parking information, traffic congestion, traffic regulation, news, and weather forecast are provided to vehicles by radio communication of radio beacons, optical beacons, and FM multiplex broadcasting. As a result, a road traffic information communication system (VICS) that enables a driver to travel on an accurate route to a destination while comprehensively judging various types of information.
(Registered trademark)) has been put to practical use. Among them, the optical beacon adopts a communication method using near-infrared light as a medium,
An optical beacon on-road device having an optical vehicle sensor and an optical signal transmitting / receiving unit is installed on a road. Various kinds of information are always transmitted from the light transmitting unit of the optical beacon roadside device as a downlink.

[0003] Various types of information obtained by this downlink include traffic congestion information, section travel time information, event regulation information, and the like included in a range from about 30 km ahead to about 1 km behind.
Parking information and the like are included. On the other hand, by transmitting a data signal such as the ID number of the vehicle from the traveling vehicle to the optical beacon on-road device on the road and performing the uplink, it is possible to measure the link travel time with high accuracy. As a result, it is possible to receive traffic congestion / travel time link information required for dynamic route guidance by a vehicle-mounted navigation device.

[0004] Further, as an apparatus for detecting a rainfall state,
For example, there is an infrared laser cutoff type or electric resistance type rain detection device as shown in FIG. 2A is a block diagram of a rain detection device of an infrared laser cutoff type, in which a light emitting unit 21 and a light receiving unit 23 are arranged to face each other, and an infrared laser output from a driving circuit 22 is transmitted from the light emitting unit 21 to the light receiving unit. Irradiate constantly toward 23. Counting unit 2 counts the number of pulses of infrared laser cut off by rainfall RN
5 counts, and the rainfall state is determined based on the number.
6 is to detect. (B) is a block diagram of an electric resistance type rain detection device. A DC power supply 31 and an ammeter 33 are connected in series to both ends of an electric resistor 32. When rainwater permeates the electric resistor 32 due to the rain RN, the electric resistance changes. Therefore, the change of the current value in the ammeter 33 is read by the judging unit 35 to detect the rain state.

[0005]

By the way, if a vehicle is equipped with a device for detecting a rain condition, dedicated hardware is required. However, the rain detection device described above has the following problems. there were. First, in the infrared laser cut-off method, the light emitting unit 21 is installed at the time of installation so that the infrared laser from the light emitting unit 21 is received by the light receiving unit 23 well.
It is necessary to adjust the optical axis of the light receiving unit 23, and even if the optical axis is set accurately once, there is a possibility that the set optical axis cannot be detected due to external vibration or the like. In addition, if the distance between the light emitting unit 21 and the light receiving unit 23 is too short, accurate rainfall cannot be performed. Therefore, it is necessary to provide a certain distance or more, and the whole apparatus is large and a large installation space is required. Furthermore, since the infrared laser was constantly irradiated, a large amount of electricity was consumed. In the electric resistance method, it takes time until the resistance value of the electric resistor 32 changes after the rain starts to fall, and it takes time until the resistance value of the electric resistor 32 returns to the original value even if the rain stops. Was hanging. That is, it was not possible to detect rainfall promptly.

The above-described optical beacon on-vehicle device includes:
It is expected that the vehicle will be standard equipment in the future, but at present, it will transmit and receive VICS information when passing through the optical beacon road machine installed on the road and enter the area where communication with the optical beacon road machine is possible. Other than the regular area confirmation of whether or not the operation has been performed, no other operation processing has been performed, and the system has not been effectively used as a hardware resource.

It is an object of the present invention to provide an on-vehicle optical beacon that can detect a rainfall condition.

[0008]

In order to solve the above-mentioned problems, the present invention is provided near a windshield in a vehicle,
In an optical beacon device for communicating traffic information, a rain detection signal for detecting a rain condition is output, and the amount of reflected light of the rain detection signal reflected on the windshield is compared with a predetermined value to detect a rain condition. It is characterized by having a control means for performing the above. Also, a light emitting unit that emits an infrared signal for transmitting uplink information, a light receiving unit that receives an infrared signal of downlink information, an information processing unit that processes the uplink information and the downlink information, A detection signal transmitting unit that transmits a rain detection signal for detecting a rainfall state to the light emitting unit when the communication of the traffic information is not performed; and the rain detection that is emitted from the light emitting unit by the detection signal transmitting unit. An infrared signal corresponding to the signal, a light intensity detecting means for detecting a light intensity reflected by the windshield and received by the light receiving unit, and comparing the light intensity detected by the light intensity detecting means with a predetermined value. Rain detecting means for detecting a rain state.

That is, according to the present invention, for example, when it is confirmed that the on-board optical beacon is not in a communication area with the on-road optical beacon, a signal for periodically detecting a rainfall state is output from the light emitting section, and The light reflected by the windshield is received by the light receiving unit, and the light intensity is detected. By comparing the detected light intensity with a predetermined value,
Since the rain state can be detected, the in-vehicle optical beacon can be used also as a rain detection device.

[0010]

FIG. 1 is a diagram showing the configuration of an on-board optical beacon according to an embodiment of the present invention. The on-vehicle optical beacon device 1 shown in FIG. 1 is connected to an on-vehicle navigation device 2 and communicates VICS information with an on-road optical beacon device installed on a road according to a predetermined communication protocol. Since the reflectance of the windshield FG of the vehicle is changed by the raindrop RN, the detection signal is emitted, and a rainfall state is detected from the amount of reflected light (detection signal) reflected by the windshield FG. A light emitting driver 12, a signal processing unit 13,
Light receiving unit 14, receiving amplifier 15, CPU 16, memory 1
7, an A / D conversion unit 18 and a determination unit 19.

The light emitting section 11 is a windshield FG of a vehicle.
It is installed nearby and outputs an infrared signal for uplink when the vehicle enters the communication area with the optical beacon road machine installed on the road, and the vehicle is not in the communication area At times, an infrared signal for detecting a rainfall state is periodically output. The light emitting driver 12 controls the light emitting unit 11 to transmit each infrared signal. The light receiving unit 13 is installed near the windshield FG of the vehicle similarly to the light emitting unit 11, and receives a downlink signal transmitted from an optical beacon on-road device on the road, or is output from the light emitting unit 11. Vehicle windshield F
An infrared signal reflected by G for rainfall detection is received.
The receiving amplifier 14 amplifies and demodulates each infrared signal received by the light receiving unit 13.

The signal processing unit 15 includes an encoder and a decoder (not shown). The encoder controls the protocol of the uplink, transmits data to the optical beacon on-road device, and detects rainfall for detecting a rainfall state. For example, the detection signal is subjected to Manchester encoding. The decoder decodes the Manchester code of the reception data amplified and demodulated by the reception amplifier 14 and performs a data reception process.

The CPU 16 outputs transmission data for the uplink and a rain detection signal for detecting rain to the signal processing unit 15 and receives various data transmitted to the light receiving unit 13 via the downlink. For the control. The various data received according to the data contents are sent to the navigation device 2, where the various data are displayed on a display unit (not shown), and the traffic congestion / travel time link information included in the various data. And performs various processes such as extracting the extracted information for use in the dynamic route guidance processing. Further, a timer (not shown) is built in, and when the rain detection signal is transmitted from the light emitting unit 11 at predetermined intervals, the predetermined time is measured.

The memory 17 temporarily stores data such as the calculation results of the CPU 16. The A / D converter 18 converts the rain detection signal amplified by the reception amplifier 14 from an analog value to a digital value. The determination unit 19 includes an A / D conversion unit 18
Then, it is determined whether or not it is raining by comparing the value converted into a digital value with a predetermined value.

The above-mentioned A / D converter 18 corresponds to the light intensity detecting means, the signal processing section 15 and the CPU 16 correspond to the information processing means, the detection signal transmitting means, and the judging section 19 corresponds to the rainfall detecting means.

The on-vehicle optical beacon device 1 of the embodiment of the present invention has such a configuration, and the processing of the present invention will be described next. FIG. 2 is a flowchart showing a rainfall detection process of the on-vehicle optical beacon to which the present invention is applied. First, the CPU 16 determines whether or not the downlink information from the optical beacon on-road device installed on the road is received by the light receiving unit 13 (step 101). The optical beacon roadside device and the on-board optical beacon device 1 perform normal VICS information communication processing (step 102).

After the communication process is completed, or when the downlink information is not received, it is determined whether or not the measurement of a predetermined time by the timer built in the CPU 16 has been started (step 103). If available, CPU
A signal processing unit 15 encodes a rain detection signal for detecting rain into a Manchester code, and
An infrared signal of a rain detection signal is output from the light emitting unit 11 via the second unit 2 and a timer is newly started to measure a predetermined time (step 105).

If the measurement is started in step 103, the CPU 16 checks the time measured by the timer and determines whether or not the predetermined time has been reached (step 10).
4). If the time measured by the timer has not elapsed the predetermined time, the flow returns to step 101 to determine whether or not the downlink information has been received by the light receiving unit 13. Is performed. That is, when the in-vehicle optical beacon device 1 is not performing the normal VICS information communication process, the infrared signal of the rainfall detection signal is changed every predetermined time (for example, 1 second) for a period of, for example, 5 msec.
The light is output from the light emitting unit 11.

After outputting the infrared signal of the rain detection signal, the on-board optical beacon 1 receives the infrared signal of the rain detection signal reflected by the windshield FG at the light receiving section 13 (step 1).
05), the amount of received light is amplified by the receiving amplifier 14, and the amplified amount of received light is converted from an analog value to a digital value by the A / D converter 18 (step 106). The determination unit 19 determines whether or not the value of the received light amount converted into a digital value by the A / D conversion unit 18 is larger than a preset value (step 107). If the value of the received light amount is larger than the predetermined value, it is determined that a rainfall state is occurring, and the rainfall detection
(Step 108). If the value of the received light amount is equal to or less than the predetermined value, it is determined that it is not raining, and
Returning to 03, the CPU 16 checks whether or not a predetermined time measured by the built-in timer has elapsed.

[0020]

As described above, according to the present invention, when the in-vehicle optical beacon is not performing traffic information communication processing, it outputs a rain detection signal for detecting a rain state,
Since the rainfall condition is detected by comparing the amount of light received by the windshield of the vehicle with a predetermined value, the rainfall condition can be detected using the on-board optical beacon without using a dedicated rainfall detection device. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an on-vehicle optical beacon according to an embodiment to which the present invention is applied.

FIG. 2 is a flowchart showing rainfall detection processing of the on-vehicle optical beacon according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating a conventional rainfall detection device.

[Explanation of symbols]

 1. Onboard optical beacon 2. Navigation device 11. Light emitting unit 12. Light emitting driver 13. Light receiving unit 14. Reception amplifier 15. Signal processing unit 16. CPU 17. Memory 18. / D conversion unit 19 ··· Judgment unit RN · · · raindrops FG · · · windshield

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01W 1/14 G01W 1/14 B

Claims (2)

[Claims] 1. An on-vehicle optical beacon installed near a windshield in a vehicle and communicating traffic information, outputs a rain detection signal for detecting rain, and the rain detection signal reflected by the windshield. An on-vehicle optical beacon device comprising a control means for detecting a rainfall state by comparing the amount of reflected light with a predetermined value. 2. An in-vehicle optical beacon installed near a windshield in a vehicle and communicating traffic information, a light emitting unit for emitting an infrared signal for transmitting uplink information, and an infrared signal for downlink information. A light receiving unit for receiving the information; an information processing unit for processing the uplink information and the downlink information; and a light emitting unit for outputting a rain detection signal for detecting a rain state when the communication of the traffic information is not performed. Detection signal transmitting means for transmitting to the infrared signal corresponding to the rainfall detection signal emitted from the light emitting unit by the detection signal transmitting means, the intensity of the light reflected by the windshield and received by the light receiving unit A light intensity detecting means for detecting, and a rain detecting means for detecting a rain state by comparing the light intensity detected by the light intensity detecting means with a predetermined value. An on-vehicle optical beacon device comprising: a step;