JPH0772715B2 - Road condition determination system - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a road surface condition determination system, and more particularly to a road surface reflectance meter and a road surface thermometer, and determines the presence or absence of moisture on the road surface based on the road surface reflectance. Further, the present invention relates to a road surface state determination system for determining road surface freezing based on the road surface temperature.

(Prior Art and its Problems) A conventional system of this type has a configuration as shown in FIG.

In the figure, 101 is a road surface reflectometer, 102 is a road surface thermometer, and each is connected to a terminal device 103. The terminal device 103 includes a conversion unit 104 that converts an analog signal from the road surface reflectometer 101 and the road surface thermometer 102 into a digital signal,
An arithmetic processing unit 105 that processes signals from the conversion units 104 ...
And are provided.

Then, the arithmetic processing unit 105 determines the road surface condition by the operation shown in FIG.

That is, first, in the signal output from the road surface reflectometer 101, when it is determined that the infrared light diffuse reflectance is larger than the set value (step 1), it is further determined whether or not the visible light diffuse reflectance is larger than the set value ( If it is larger than the set value, a dry state signal is output (step 3), and if it is less than the set value, a dry state signal is output (step 4). In step 1, the visible light diffuse reflectance is also determined when it is determined to be less than or equal to the set value (step 5), and when it is greater than the set value, a snow jam condition signal is output (step 6). When it is determined in step 5 that the visible light reflectance is less than or equal to the set value, the signal from the road surface thermometer 102 is further determined (step 7), and when the temperature is lower than the set value, the frozen state signal is output. (Step 8) If the value is equal to or more than the set value, a wet state signal is output (Step 9). The respective road surface condition signals thus obtained are sent to the central device 106 side.

However, in the case of the conventional example having such a configuration, since the presence or absence of road surface moisture is determined only from the infrared light diffuse reflectance data on the local road surface of a wide range of determination target roads, an accurate determination cannot be performed. was there. That is, if there is water or condensation on the part of the road surface corresponding to the infrared reflectance meter, it is judged whether it is wet or freezing even if the road surface in the area is dry, and conversely draining water. When the corresponding portion is in a dry state due to factors such as the sun, the sun, etc., there is a drawback that the determination of dryness is made regardless of whether the road surface in the area is wet or frozen.

(Object of the invention) The present invention has been made in view of the above circumstances, and it is possible to make the determination more reliably by performing the determination of the presence of road surface water based on the precipitation detection. With the goal.

(Structure and Effect of the Invention) In order to achieve such an object, the present invention provides a road surface condition determination system described at the beginning, with a precipitation detector, and after the presence / absence of water on the road surface is determined, the precipitation detection is performed. In response to a signal from the vessel, a road surface moisture determination means is provided to re-determine the presence or absence of moisture on the road surface based on the presence or absence of precipitation within a set time.

According to this configuration, after the road surface moisture determination based on the road surface reflectance, the road surface moisture determination means responds to the signal from the precipitation detector, and when there is precipitation within the set time, there is water on the road surface, If there is no precipitation within the set time, it is determined that there is no water on the road surface.

Therefore, since the erroneous road surface water content determination due to wetting, freezing and drying on the local road surface is corrected by the road surface water content determining means, it becomes possible to accurately determine the presence or absence of the road surface water content, which corresponds to the actual road condition. You can now judge the road condition.

(Description of Embodiments) Hereinafter, the present invention will be described in detail based on embodiments illustrated in the drawings. FIG. 1 is a block diagram showing the overall configuration of the road surface condition determination system of the present invention.

In the figure, 1 is a precipitation detector, 2 is a road surface reflectometer, 3 is a road surface thermometer, 4 is a thermometer, and each is a terminal device 5.
It is connected to the. The terminal device 5 includes a conversion unit 6 for converting an analog signal from the road surface reflectometer 2, a road surface thermometer 3, a temperature meter and 4 into a digital signal, and those conversion units 6 and the precipitation detector 1. An interface section 7 for receiving a signal, a first transmission control section 8 for editing signal data from the interface section 7 and performing parallel-to-serial conversion, and a modulation section 9 serving as a transmission section to the center side are provided. ing.

The central unit 10 includes a demodulation unit 11 that receives a signal from the terminal side.
A second transmission control unit 12 that performs parallel-to-parallel conversion of the data signal from the demodulation unit 11, a monitoring control unit 13 that determines the road surface state based on the data signal from the second transmission control unit 12, and a monitoring control unit 13
A memory that stores the judgment program for making judgments.
A conversion unit 15 for converting the judgment output from the monitoring control unit 13 into an analog signal; a dot gauge 16 connected to the conversion unit 15 and showing the judgment confirmation contents; and a floppy disk 17 for accumulating the judgment output from the monitoring control unit 13. And are provided. The floppy disk 17 is for loading / saving programs.

The road surface determination means in the present invention is provided in the monitor control unit 13, and its operation will be described in the following operation description.

Next, regarding the operation of this embodiment, the monitoring control unit of FIG.
It will be described with reference to a flowchart showing the operation of 13.

First, it is judged whether or not the infrared diffuse reflectance in the signal from the road surface reflectometer 2 is larger than a set value (for example, 40%) (step 1). It is judged whether the diffuse reflectance is larger than the set value (for example, 40%) (step 2). When the value is large in the fresh snow accumulation state, a snow accumulation (fresh snow) determination signal is output (step 3) and the operation is ended. If it is determined in step 2 that there is no snow and the diffuse reflectance of visible light is less than or equal to the set value, then based on the signal from the precipitation detector 1, was there no precipitation or snowfall within the set time (for example, 60 minutes)? (Step 4), if there is not, a dryness determination signal is output (Step 5) to end the operation, and if there is precipitation or snowfall, a wetness determination signal is output (Step 6). To finish.

Even if it is determined in step 1 that there is water on the road surface and the infrared diffuse reflectance is below the set value, it is determined whether or not the visible diffuse reflectance is larger than the set value (for example, 40%) (step 7). If there is snow (snow jam) and the value is large, a snow accumulation (snow jam) determination signal is output (step 8) and the operation ends. In step 7, when it is determined that there is no snow and the diffuse reflectance of visible light is less than or equal to the set value, it is determined based on a signal from the precipitation detector 1 whether there is no precipitation or snow within the set time (for example, 60 minutes) ( If it is determined that there is no precipitation or snowfall in step 9), the process proceeds to step 5 and a dryness determination signal is output.
If it is judged that there is precipitation or snowfall in step 9, it is judged whether or not the road surface temperature is lower than the set value (for example, -2 ° C) based on the signal from the road surface thermometer 3 (step 10). Further, based on the signal from the thermometer 4, it is judged whether or not the temperature is lower than a set value (for example, 5 ° C) (step 11), and if it is lower, a freeze determination signal is output (step 12) and the operation is ended. To do. Step
If the value is greater than or equal to the set value in step 10 and step 11, the process proceeds to step 6 to output the wetness determination signal.

As described above, the monitoring control unit 13 once determines the presence / absence of road surface moisture in step 1, and then performs the determination operation of the presence / absence of road surface moisture again in steps 4 and 9 by the road surface moisture determination means. There is. By operating in this way, even if an erroneous determination limited to the local road surface of the road is made in Step 1, the determination is corrected in Steps 4 and 9.

Further, in the above-described embodiment, the freezing determination is performed based on the signal from the air temperature meter 4 in addition to the signal from the road surface thermometer 3. Therefore, in the determination based on only the road surface thermometer 3, there is no shade. Therefore, the disadvantage that the local road is erroneously determined to be frozen due to the local road surface being frozen is solved.

Further, in the above-described embodiment, the monitoring contents are determined by the monitoring person by the supervisor.
However, it is also possible to connect a higher-level device to the central device 10 so that the central device 10 is automatically displayed on a display provided on the road.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a road surface condition determination system of the present invention, FIG. 2 is a flow chart showing the operation of a monitoring control unit, and FIG. 3 is a block diagram showing the configuration of a conventional example. The figure is a flowchart showing the operation of the conventional example. 1 is a precipitation detector, 2 is a road surface reflectometer, 3 is a road surface thermometer,
13 is a monitoring control unit (road surface moisture determination means).

Claims (1)

[Claims] 1. A road surface condition judging system comprising a road surface reflectometer and a road surface thermometer, for judging the presence or absence of water on the road surface based on the road surface reflectance, and for judging freezing of the road surface based on the road surface temperature. In the above, in the case of the precipitation detector and the determination of the presence or absence of water on the road surface, in response to a signal from the precipitation detector, the presence or absence of water on the road surface is re-determined based on the presence or absence of precipitation within a set time. A road surface condition determination system comprising: a determination unit.