JPH0135400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device formed by a cooperative combination of a plurality of active and passive electronic elements that provide reliable electromagnetic information and horizontal marking elements that provide reliable visual information. .

In view of the increasing traffic volume and the increasing trend of average vehicle speeds, the problem of road signs that provide vehicle drivers with complete information about the road is becoming increasingly important. and improve the reliability and completeness of the data that should be provided to timely warn vehicle drivers of, for example, approaching dangerous intersections and/or potentially dangerous road sections, etc. It is believed that in order to achieve this goal, it is absolutely necessary to organize information.

Although several proposals and attempts have been made in the past regarding these problems, they are far from being solved. For example, one proposal is to install transmitting active elements at dangerous points on the road, which supply the required data or information to receiving elements on board the vehicle. However, with this method, the number of active elements required to protect all dangerous parts and places is extremely large, and it is necessary to supply and control current to make these active elements work continuously. This would result in a complex and extremely expensive configuration. It is clear that lack of warning signals and/or oversight or misidentification leads to the most serious crashes.

On the other hand, it is recognized that current road markings, both vertical and more efficient horizontal ones, are far from providing an adequate solution to the above-mentioned problems. With the exception of audible signals issued between vehicles, current signage or road signaling systems require visual detection of signals and constant attention to the direction of travel. This visual detection is sensitive to visibility conditions, e.g. season, weather, etc., and is therefore suitable for receiving and demodulating sign data to signal the driver (and/or vehicle instruments). It is now considered to be an essential requirement from the viewpoint of vehicle traffic safety to provide a vehicle with such a device.

In view of these circumstances, the present invention provides: a tape-like element that is installed on a road and constitutes a horizontal sign element that is visually recognized by a driver; , a passive element which, when an electromagnetic wave of a first frequency is input, emits an electromagnetic wave of a second frequency different from the first frequency without being supplied with external power supply energy; an active electronic circuit that outputs the electromagnetic wave of the first frequency to the passive element integrally provided on the tape-shaped element and receives the second frequency radiated from the passive element; A composite device for marking is provided.

Even when the above configuration of the present invention is followed, especially when the active electronic circuit mounted on the vehicle is configured as a secondary radar, which has a function of transmitting electromagnetic waves of a first frequency and a function of receiving electromagnetic waves of a second frequency. , the passive elements provided integrally with the tape-like element are spaced apart from each other at appropriate intervals along the length of the tape-like element,
It can be a dipole antenna arranged in spots.

Such a dipole antenna is generally known as a "responder", but when applied to the present invention, it uses electromagnetic waves of the first frequency transmitted by an active electronic circuit mounted on a vehicle. It is possible to use a thin metal plate whose size and shape are appropriately selected so as to form a resonant circuit that resonates. When the first frequency is input, it resonates and multiple harmonics are output from the dipole antenna. Among them, if the third harmonic is used as the electromagnetic wave of the second frequency, this It is desirable because it has the highest energy intensity.

The tape-like element itself may be made of any suitable material as long as its surface forms a road sign that can be visually recognized by the driver, and it is not a single layer, but has a surface. It may have a two-layer structure with a primer layer or a lower layer below the layer.
In this case, the above-mentioned dipole antennas as passive elements, for example, may be formed in advance so as to be integrally sandwiched between the surface layer and the lower layer, or may be integrally provided on the back surface of the lower layer. .

In any case, it is sufficient that the passive element and the tape-like element are already integrally assembled before the tape-like element is actually installed on the road.

In fact, the applicant has also confirmed that such a tape-like element can effectively function as a support for a dipole antenna having a thin sheet metal.

The advantages of the invention are obvious. For example, if the dipole antenna described above is used as a passive element and a radar circuit is used as an active electronic circuit mounted on a vehicle, whether or not electromagnetic waves of a second frequency are received relative to radiation of electromagnetic waves of a first frequency; The reception interval can be obtained depending on whether a dipole antenna is present or not, that is, the arrangement of each dipole antenna and the mutual spacing, so this can be widely used as road information.

Furthermore, there is no need to supply power energy to the dipole antenna from the outside, and it is sufficient to simply install a tape-shaped element that has passive elements integrally in advance on the road, which not only improves work efficiency. As seen in the conventional example described above, there is no drawback of the transmitting/receiving device provided on the roadside, which requires constant power supply.

It would be extremely dangerous if the equipment installed on the roadside, which is a public facility, were to lose its function as an electromagnetic road sign if the power went out (and there is a good chance that this would happen), as was the case in the past. Yes, it cannot actually be adopted.

It should be noted that, in addition to the device of the present invention, if auxiliary resonant elements, also made of small metal plates, are installed along the road, the amount of information will be further increased and the active electronic circuits mounted on the vehicle will be By introducing a computer, it is possible to perform optimal coding and decoding regarding information processing.

Recent developments in radar equipment for the purpose of preventing collisions in dense fog are well known. The present invention is also effective if such a device is modified and utilized.

Information such as weather conditions can also be provided in the same way. For example, if a pre-recess is formed in the capacitive circuit of a dipole, very valuable information (presence of ice on the road) can be obtained since the presence of ice in this recess significantly changes the response parameters. provided.

Some other supplementary information can be obtained by associating the system, and in particular the active element, with an infrared light source that can be returned to and modulated by the passive element, respectively. Assignee's U.S. Patent No. 4129397
No. 6,006,902 discloses a road marking strip having reflective repeller elements that are easily modifiable and adaptable to reflect infrared energy. It is known that a large amount of information can be obtained using this suitably modulated energy.

Furthermore, because it is quick and easy to temporarily place signal strips or tapes on road pavements, the system of the present invention, in addition to continuously providing locally pre-programmed information, also provides temporary It is also possible to provide services, for example to warn the vehicle driver about road interruptions or other events.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. As shown diagrammatically in FIG. 1, the vehicle V is equipped with a known secondary radar R having a dipole antenna fixed under the vehicle body, etc. moving above. The active element R is connected to a dipole (an example of which is shown in FIGS. 2 and 3) in a signal strip S (only one strip is shown along road A for simplicity). It is preferably computerized using known techniques to demodulate the information obtained by the re-radiated electromagnetic waves. This signal strip can be used as a continuous strip S ₂ or as a spaced strip S ₁
For example, the former may be assigned an area where overtaking is prohibited, and the latter may be an area where overtaking is allowed. The information corresponding to each portion S ₁ , S ₂ (an uninterrupted series of spaced signals and a series of short spaced signals, respectively) is transferred to a computerized active element R.
to the vehicle via.

The above is an example of basic coding, and for example, a coding example as shown in FIG. 4 can also be considered. In this, different series of signals, e.g. an equal sequence C, give a response regarding the speed of the vehicle, while different groups G ₁ , G ₂ , G ₃ have their respective meanings preferably coded. There is. A resonant circuit consisting of a dipole re-radiates multiple harmonic energy, with the third harmonic being the strongest and therefore preferably utilized.

Fairly high frequencies are used so that the antenna of the required resonant circuit can be constructed as a dipole in a metal sheet, such as aluminum, of dimensions that can be embedded in the strip layer.

For example, a transmitting/receiving assembly, i.e. a secondary radar having the active elements of the system on the vehicle, preferably utilizes microwaves in the range of 0.6 to 1.2 GHz in transmission.

In practice, for best results, the transmitting antenna and resonant dipole are placed transversely to the signal line. This sets a limit for the lowest frequency (a 25cm long dipole is 600M
Hz). There is no particular limit to the higher frequency, but it is desirable to satisfy requirements such as not increasing the price too much, not having too much sensitivity to humidity, and not increasing the loss coefficient of the material. However, in practice, the frequencies selected for current anti-collision radar systems will be used.

For example, if a transmitter with a frequency of 1 GHz and a power of 0.5 watts is used, at a distance of 5 m from the signal strip and at a vehicle speed of 20 km/h, the dry road map will
A third harmonic response of 1.4 microvolts was obtained,
On the other hand, in the case of a wet road surface, it was 1.55 microvolts.

The passive dipole, generally indicated by D in FIGS. 2 and 3, may have any shape, size, or configuration as long as it can form a resonant circuit responsive to signals emitted from the secondary radar. Similarly, the characteristics of the secondary radar may vary with frequency.

Therefore, the manner in which the passive dipole is installed can vary, for example by placing it under a preformed signal layer or marking layer, by gluing a strip, by attaching a tape to a supporting underlayer (primer), etc. It may also be arranged as a ribbon.

In this way, a preformed strip with reflective or resonant passive elements placed under a suitable signal layer can serve as a visually visible horizontal beacon and be selected for secondary radar on vehicles. The dual function of providing electromagnetic information by resonating elements is demonstrated.

Although described above, the present invention is not limited to the examples in accordance with the gist thereof.

[Brief explanation of drawings]

1 is an illustration of a road section A with a marking strip having a series of dipoles, each forming an individual resonant circuit; FIG. 2 is a partial configuration of a strip S with dipoles D made of thin stamped aluminum plates etc. Figure 3 shows the variable vibration circuit
Partial diagram of another embodiment of a dipole with D _s ,
FIG. 4 is an explanatory diagram of another code example. In the figure, A is a road, D is a variable dipole, _Ds is a variable vibration circuit, R is a secondary radar, S is a signal strip, and V is a vehicle.

Claims (1)

[Scope of Claims] 1. Tape-like elements S, S1, and S2 that are installed on the road A and constitute horizontal sign elements that are visually recognized by drivers; a passive element D that is integrally provided on the back surface and radiates electromagnetic waves of a second frequency different from the first frequency when an electromagnetic wave of a first frequency is input without receiving an external power supply; The electromagnetic wave of the first frequency is output to the passive element D mounted on the running vehicle V and integrally provided with the tape-like elements S, S1, S2, and the electromagnetic wave radiated from the passive element D. an active electronic circuit R for receiving said second frequency; and a composite device for a road sign. 2. The device according to claim 1, wherein the passive element is a dipole antenna. 3. The device according to claim 2, wherein the first frequency and the second frequency are values in a radar frequency range. 4. The device according to claim 2 or 3, wherein the second frequency radiated from the dipole antenna is a third harmonic generated by resonance of the first frequency. 5. The active electronic circuit mounted on the vehicle has a computer that processes information provided by electromagnetic waves of a second frequency, as described in any one of claims 2 to 4. equipment. 6. The dipole antenna has a recess in its capacitive circuit portion, and the second frequency changes depending on the presence or absence of ice in the recess. Any one of the devices listed.