JP2001228265A - Road-surface antifreezing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a road-surface antifreezing system wherein, being excellent in energy efficiency, a freezing place on a road surface is predicted, and an antifreezing means is applied to the place for safe traffic on a road. SOLUTION: A master station 1 and a plurality of slave stations 2 provided, with interval, in the longitudinal direction of a road 7, are connected with a transmission path 3, thus a road-surface antifreezing means 9 which prevents freezing on a road surface G of the road 7 installed. The slave station 2 comprises an atmospheric temperature sensor 4, road-surface temperature sensor 5, and a water-amount sensor 6 for measuring the water amount on the road surface, and is added with a function where the information from the sensors is converted into electric signal, which is transmitted to the master station through the transmission path 3. The master station 1 is equipped with a function wherein a place of the road surface G which is possible to be frozen is predicted based on the electric signal transmitted from the slave stations 2 and the road-surface antifreezing means 9 is made to apply an antifreezing measure to predicted place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intelligent road information system (ITS), and more particularly, to predicting a freezing point on a road surface of a road in advance and taking measures to prevent freezing to prevent accidents and the like. Road freeze prevention system.

[0002]

2. Description of the Related Art Generally, when a road surface freezes, slip accidents, rear-end collisions, etc. occur frequently, and the traffic is paralyzed. ing. In order to provide such information, various systems for determining a road surface state have been conventionally proposed. For example, Japanese Unexamined Patent Publication No. Hei 5-71111 discloses that the road surface condition is determined based on the air temperature and the road surface temperature at the observation point measured by the optical fiber temperature sensor and the road surface moisture measured by the road surface moisture detector. A system for displaying results on a display device installed on a road is disclosed.

However, the above-described system merely determines whether or not the road surface is frozen and provides information on the determination result, and does not attempt to defrost the frozen road surface. Therefore,
In order to avoid the danger of freezing on the road surface, for example, the driver attaches a chain to the tires according to the indication on the display device to take anti-slip measures, or a management agency that manages the road sprays an anti-freezing agent. It is necessary to take measures to prevent freezing. For this reason, despite the introduction of the above system, accidents due to road surface freezing due to delays in chain attachment, application of antifreeze, and insufficient application of antifreeze were It has occurred.

Further, the above-mentioned system determines whether or not the road surface is frozen, and does not predict a frozen location. Therefore, although there is no freeze indication, there is a case where the road surface is actually slippery and dangerous, and there is a problem that such a danger cannot be avoided by the above-mentioned system.

On the other hand, a road heating system (hereinafter referred to as an "RH system") for warming a road surface to prevent the road surface from being frozen has been put into practical use as a system for avoiding an accident due to road surface freezing, separately from the above information providing system. Yes,
It is mainly laid at toll booths such as expressways, tunnel entrances, bridges, slopes, curves and the like. Generally, the RH system is configured by burying a heating wire or a hot water pipe in the ground in a meandering manner. The RH system is provided with a temperature sensor for measuring road surface temperature, a road surface moisture detector for measuring road surface moisture, and the like. The RH system is operated based on information from these.

However, the conventional RH system does not operate while monitoring the frozen state of the road surface by receiving information from a temperature sensor or a road surface moisture detector at any time. The information from was only used as a yardstick to determine if it would work. That is, in the conventional RH system, the operation is merely performed when the manager determines that the road surface is frozen or may be frozen based on information from the temperature sensor, the road surface moisture detector, and the like. During the operation, only operations such as always running were performed. In addition, the suspension of the operation is left to the judgment of the administrator, and even if the defrosting of the road surface has already been completed, the operation may be kept in an operating state. As described above, the conventional RH system is operated only by ON / OFF by the administrator, and it can be said that the energy efficiency is extremely low.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, to predict a frozen spot on a road surface in advance, and to take measures to prevent the freezing of the spot, thereby ensuring road safety. Another object of the present invention is to provide a road surface freezing prevention system having excellent energy efficiency.

[0008]

The road surface freezing prevention system according to the present invention has the following features. (1) Road surface freezing prediction means in which a master station and a plurality of slave stations arranged at intervals along the longitudinal direction of the road are connected via a transmission line, and to prevent freezing of the road surface of the road Wherein the slave station measures a temperature sensor for measuring an atmospheric temperature, a temperature sensor for measuring a road surface temperature of a road, and a water content of a road surface of the road. And at least a moisture content sensor for converting information from each sensor into an electric signal and transmitting this to a master station via a transmission line.The master station is transmitted from each slave station. A road surface freezing prevention system for predicting a possible freezing point on a road surface based on an electric signal and causing road surface freezing prevention means to prevent the predicted freezing point.

(2) The road surface freezing prevention system according to (1), wherein the transmission line is a metal cable formed by coating a metal conductor with an insulating material.

(3) The road surface freezing prevention system according to the above (1), further comprising a power cable for supplying power from the master station to the slave station, wherein the power cable is arranged in a bundle with the transmission line.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of the road surface freezing prevention system of the present invention. In the figure, each part is schematically shown. As shown in the example of FIG. 1, in the road surface freezing prevention system of the present invention, a master station 1 and a plurality of slave stations 2 arranged at intervals along the longitudinal direction of the road 7 via a transmission path 3. It has a road surface freezing prediction means connected thereto and a road surface freezing prevention means 9 for preventing the road surface G of the road 7 from freezing.
Reference numeral 8 denotes a power cable for supplying power from the master station to the slave stations.

The slave station 2 has a temperature sensor (hereinafter, referred to as an "atmospheric temperature sensor") 4 for measuring the atmospheric temperature and a temperature sensor (hereinafter, referred to as "temperature sensor") for measuring the temperature of the road surface G of the road 7.
“Temperature sensor for road surface temperature”) 5 and a water content sensor 6 for measuring the water content of the road surface G of the road 7. The slave station 2 has a function of converting information from each of the sensors (4 to 6) into an electric signal and transmitting the electric signal to the master station 1 via the transmission line 3. The master station 1 has a function of predicting a place where the road surface G may be frozen based on the electric signal transmitted from each slave station 2 and causing the road surface freezing prevention means 9 to prevent the predicted place from being frozen. Have.

As described above, in the road surface freezing prevention system of the present invention, since the freezing point is predicted in advance and the freezing prevention measure is applied to the freezing point, it is conventionally possible to avoid an accident due to the road surface freezing. It can be even higher. Further, the road surface freezing prevention system of the present invention performs freezing prevention while constantly monitoring the freezing state based on information from the slave station 2, so that it is operated efficiently without waste of energy compared to the conventional RH system. You.

In the example shown in FIG. 1, a thermocouple is used as the temperature sensor 4 for atmospheric temperature and the temperature sensor 5 for road surface temperature. The thermocouple is composed of two types of conductors and utilizes a thermoelectromotive force generated by a temperature difference. In the present invention, these temperature sensors are not particularly limited, and other known temperature sensors can be used. In the present invention, the thermocouple may be a noble metal thermocouple or a base metal thermocouple.

Temperature sensor 4 for atmospheric temperature in one slave station
Is composed of one thermocouple. In the present invention, the number of thermocouples constituting the temperature sensor for atmospheric temperature 4 is not limited, and may be two or more. The thermocouple constituting the temperature sensor 4 for the ambient temperature has a height of 5 mm from the road surface in order to avoid the influence from the road surface such as reflected light and vehicle splashing water.
It is preferable to set at a position of 0 cm to 200 cm.

The road surface temperature sensor 5 in one slave station is
It is configured by embedding three thermocouples at equal intervals in the depth direction. The measurement of the road surface temperature is performed by obtaining a temperature gradient in the depth direction from these three thermocouples and estimating the road surface temperature based on the temperature gradient. In particular,
Each of the road surface temperature sensors 5 sent by the master station 1 from the slave station 2
The road surface temperature is calculated based on this information. The number of thermocouples constituting the road surface temperature sensor 5 is not particularly limited, but is preferably three or more from the viewpoint that the road surface temperature can be accurately measured. It is preferable that the road surface temperature sensor be exposed from the road surface in order to improve the accuracy of the road surface temperature. However, if the road surface temperature sensor is exposed from the road surface, the road surface temperature sensor is easily damaged and the durability is deteriorated.

In the example shown in FIG. 1, an electrode type moisture sensor is used as the moisture sensor 6 for measuring the moisture on the road surface G. The electrode-type moisture sensor comprises one or more pairs of electrodes and an insulator that insulates the electrodes, and is installed so that a part of the electrode pair and a part of the insulator are exposed from a road surface. (See Japanese Patent Publication No. 5-71916 and Japanese Patent Publication No. 5-28540). Therefore, when there is no moisture on the road surface, the electric resistance between the electrodes is extremely large, but when there is moisture on the road surface, the electric resistance between the electrodes becomes small. In the electrode type water content sensor, the water content is measured by the change in the electric resistance. In the present invention, the moisture content sensor 6 is not particularly limited, and a known moisture content sensor other than the electrode type moisture content sensor can be used.

In the example shown in FIG. 1, the slave station 2 is configured by housing a one-board computer in a waterproof / dustproof case. The one-board computer includes a communication board for connecting to the transmission line 3, a power supply board for connecting to the power cable 8, an insulating board for connecting to various sensors (4 to 6), and an AD converter. Provided. In addition, the one-board computer has various sensors (4 to 6)
When the analog information is taken in from the master station, it is converted into a digital signal and transmitted according to the instruction of the master station.

In the present invention, the mode of the slave station 2 is not limited to the above-described mode. In the present invention, the installation interval between slave stations and the number of slave stations are not particularly limited, and can be set as appropriate according to the width and the total length of the target road. Also, the number of slave stations can be increased or decreased after the system is installed.

In the example shown in FIG. 1, the master station 1 comprises a computer and an electrode supply device. A communication board for connecting to the transmission line 3 is provided in an expansion slot of the computer,
A communication board for controlling the road surface freezing prevention means 9 is incorporated. On the hard disk of the computer of the master station 1, software for operating the master station is installed. With this software, the master station 1 predicts a location where the road surface G may be frozen on the basis of the digital signal transmitted from each slave station 2,
To prevent freezing at the predicted location. The master station 1 manages each slave station 2 by assigning an address, and controls transmission from the slave station in a polling system.

The prediction of a location where there is a possibility of freezing by the master station 1 is performed by judging whether or not there is a possibility of freezing from data of the atmospheric temperature, the road surface temperature and the road surface moisture for each child station. If there is a possibility of freezing as a result of the determination, the vicinity of the slave station is a place where there is a possibility of freezing. When predicting freezing from atmospheric temperature, road surface temperature, and road surface moisture,
Depending on the environment of the expected freezing place, the relationship between the above three requirements differs. For example, if the road surface moisture exceeds the specified amount and the road surface temperature or the atmospheric temperature becomes around 0 ° C. to 3 ° C., there is a possibility of freezing. And make a judgment. In this case, the anti-freezing means located at the position closest to the slave station is operated, and the anti-freezing portion is prevented from being frozen.

The master station 1 can be further provided with means for obtaining weather information. Examples of such means include means for capturing AMeDAS weather information and sunflower images published on the Internet, specifically, communication devices such as a modem built in or external to a computer, a terminal adapter, and a dial-up router ( (Including driver software for controlling them) and software for connecting to the Internet. The accuracy of the prediction can be improved by adding the latest weather information published on the Internet as a judgment factor of the prediction and performing the prediction based on the weather information and the signal from the slave station.

In the example shown in FIG. 1, a metal cable formed by coating a metal conductor with an insulating material is used as the transmission line 3. As the power supply line 8, a heat-resistant vinyl electric wire (HI
V) is used. FIG. 2 is a diagram showing the transmission line 3 and the power supply line 8 used in FIG. As shown in the example of FIG. 2, a transmission line 13 is provided alongside the transmission line 3 as a backup when the transmission line 3 is disconnected.
The transmission line 13 is omitted in the example of FIG. The transmission path 3 and the transmission path 13 are shielded together by a shield 14 and are in a twisted state. The transmission path 3 and the transmission path 13 form a twisted pair. further,
The transmission path (3, 13) and the power cable 8 are connected to a cloth tape 11
Bundled together to form a metal composite cable. Reference numeral 12 denotes an inclusion. As the inclusions 12,
A hemp string called jute is used.

As described above, in the road surface freezing prevention system of the present invention shown in FIG. 1, no optical fiber cable is used, and all the cables are metal cables. For this reason, a system can be constructed at a lower cost than when an optical fiber cable is used. In addition, since all cables are made of metal cables, adverse effects due to electromagnetic induction and switching surge can be considered. However, in the example of FIG. It is possible to use a coupler or the like so that there is no problem.

In the example of FIG. 1, a plurality of anti-freezing means 9 are provided corresponding to the slave stations 2, and are constructed by meandering heating wires. In the example of FIG. 1, the heating wire is drawn in a state of being buried meandering in the depth direction.
Is embedded so as to meander in the direction of the plane. In the present invention, the outer diameter and constituent material of the heating wire constituting the antifreezing means 9 are not particularly limited. In the present invention, a hot water pipe may be used instead of the heating wire.

[0026]

As described above, by using the road surface freezing prevention system of the present invention, it is possible to take measures to prevent freezing before the road surface is frozen, so that the safety of the road can be made more reliable than before. Can be. Further, since it is possible to prevent freezing only at locations where freezing is predicted, waste of energy can be eliminated.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a road surface freezing prevention system of the present invention.

FIG. 2 shows a transmission line 3 and a power supply line 8 used in FIG.
FIG.

[Explanation of symbols]

 Reference Signs List 1 master station 2 slave station 3 transmission line 4 temperature sensor for atmospheric temperature 5 temperature sensor for road surface temperature 6 moisture content sensor 7 road 9 freezing prevention means G road surface

Claims (3)

[Claims] 1. A road surface freezing predicting means comprising a master station and a plurality of slave stations arranged at intervals along a longitudinal direction of a road via a transmission line, and a road surface freezing prevention means for preventing the road surface from freezing. A road surface freezing prevention means for performing a temperature sensor for measuring the atmospheric temperature, a temperature sensor for measuring the road surface temperature of the road, and a water content of the road surface of the road. It has at least a moisture content sensor for measurement, converts information from each sensor into an electric signal, and transmits this to a master station via a transmission line.The master station transmits from each slave station. A road surface freezing prevention system that predicts a location on the road surface where there is a possibility of freezing on the basis of the electric signal and causes the road surface freezing prevention means to prevent the predicted location from freezing. 2. The road surface freezing prevention system according to claim 1, wherein the transmission line is a metal cable formed by coating a metal conductor with an insulating material. 3. The road surface freezing prevention system according to claim 1, further comprising a power cable for supplying power from the master station to the slave station, wherein the power cable is arranged in a bundle with the transmission line.