JPS6015532A - Road water level measuring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a road water level measuring device for identifying the presence of water or other liquids that may cause slip accidents on the road.

Generally, it is widely known that when a large amount of water is present on a motorway due to rain or other causes, abnormal slips occur due to sharp curves or sudden braking, which can lead to accidents.

In particular, the ``hydroplane phenomenon'' caused by high-speed driving on expressways is feared as an abnormal phenomenon that cannot be countered. Furthermore, it is extremely dangerous when water on the road surface freezes during the cold season.

For this reason, motorway administrators are required to constantly measure the moisture on the road surface, and currently, fixed hygrometers are generally installed at key points.

However, since the occurrence of slips on the road surface is related to the amount of moisture at a humidity of 100% or more, there is a problem in that there is a lack of direct correlation with humidity. Since the presence of broken water in localized areas is particularly dangerous, it is necessary to survey the entire road, thus requiring mobile survey methods.

SUMMARY OF THE INVENTION It is an object of the present invention to advantageously solve the above-mentioned problems and provide a device that continuously measures and quantitatively displays the extent to which water on a road surface constitutes a water surface.

Next, the principle of the present invention and the operation of the second configuration will be explained in detail using illustrated examples.

Generally, as shown in Figure 1, when natural light 4 such as sunlight or electric lights is projected onto a smooth surface, such as a water surface, at an incident angle θ0, the reflected light will be a perfect straight line if the following conditions are met. It is known that the light becomes polarized. (Brewster's law) tan θ'=1 (n: refractive index of reflective surface material) The angle θ' in this case is called the polarization angle, and in the case of water, it is n''-1,6θ'' increase of 52.4.

On the other hand, in the case of diffuse reflection where there is no water surface on the road surface 2 as shown in FIG. 2, since the reflected light is natural light 4, the light passing through the filter 6 is approximately 100%.

On the other hand, the natural light 4 projected by the projector 1 at an incident angle 52 and reflected by the water surface 6 -) t5 is polarized light, so when it passes through a polarizing filter 6'fr whose polarization plane is orthogonal to that, almost no light passes through it. %.

In reality, as shown in FIG. 6, it is normal that a part 2 of the road surface is exposed and a part forms a water surface 6, and in this case, the reflected light becomes natural light containing polarized light 5.

1 In Fig. 4, a combination filter 6 is shown in which - is an eccentric filter a and f is a simple glass b.
be installed before.

FIG. 5 shows the state of passing light under various conditions when this combination filter 6 is installed.

Figure 5 shows the case where there is no water surface at all, and all the light passing through is natural light, so the amount of light passing through polarizing filter a is (
a), and the amount of light passing through filter b is (b), then (a
), (b) are both 100%, (a)-(b)-10
0:(a)/(b)21.

(B) is a case where there is a slight water surface, for example (a
)-70, (b)=100: (a)/(b)-0,
It becomes 7.

(O is the case where there are more water surface parts, for example (a)-3
0, (b) = 100: (a)/(b) - 0,6.

(2) is the case where there is only the water surface, (a) = 0,
(1))-100(a)/(b)=0.

In other words, the proportion occupied by the water surface can be defined as follows.

Water surface ratio: α= C1(a)/(b)) X 100%
In this case, natural light is also measured at the same time.

For example, if the vehicle body moves up and down due to vibrations and the original axis of the light receiver deviates from the original axis of reflection, this can be known from Φ)-〇.

Next, an outline of an apparatus using the above principle will be explained. 6th
, 7 shows an embodiment of the present invention, in which the measuring device 9 is a measuring wheel 8.
The processing device 1° is installed inside the vehicle.

This is to prevent the measurement road surface from being affected by splashing water etc. generated by the wheels. The light projector 1 is set to point toward the road surface at approximately the center of the vehicle body and has a projection angle of 52 degrees, and the light receiver 7 equipped with the combination filter 6 is installed on the reflection angle line. A cover is provided at an appropriate position to prevent sunlight from directly hitting the road surface to be measured. Fig. 8 shows a block diagram outlining the configuration of this device.

The projector 1 may emit light continuously, but strong light is required for high-speed tracking during the day, so a single strobe light emitting method will be described in this embodiment.

measurement distance interval], tm), the emission interval t
(see) is t (sec)- if the vehicle speed is Vm/s
” - CrowL V (rrV/s) The light emitting unit 11 receives data from the speedometer 12, and
The light emission interval can be arbitrarily selected by adjusting the adjustment knob 1 to set the desired measurement interval.

Inside the light receiver 7, a photosensitive element is divided into a light receiving part for the light passing through the polarizing filter a and a light receiving part for the light passing through the polarizing filter b. The amount of light received by each of the light receivers 7 is transmitted to the measuring section 14 through two conductive wires, where it is amplified and sent to the calculating section 15 as a digital quantity.

The calculation unit 15 calculates (a) / based on the amount of received light of (a) and (b) transmitted at each instruction interval from the light emitting unit.
(b).

The data is sent to the recording unit 16 and recorded on a cassette tape or the like as digital data such as distance (position) versus water surface ratio.

Then, at the same time or when desired, the data can be displayed on the display window 18 of the display section 17 for monitoring, or the printer 19 can print out the data and store it in the case 2D and print it out through the lower glass window 21.
is kept clean at all times by the water spray nozzle 22 and the wiper 2 filter.

This example is a case of one optical receiver.

The photodetector 7 may be a dedicated one for each of the polarized temperature range and natural temperature range.

It is also possible to record all principal amounts continuously as continuous analog data and display it digitally only if it exceeds a specified value.

As explained above, the present invention is based on nμ7 of the projector 1.
The composition ratio of the road surface can be quantitatively measured by projecting 14mj (2) at ->i' and angle I3: and measuring the reflection source through a polarizing filter. You can expect good results.

(1) The composition ratio of the water surface can be measured quantitatively, and the correlation with slip becomes clear.

(2) Since continuous measurement and recording can be performed using running vehicles, entire route surveys can be carried out efficiently and economically.

(3) Since it can be fully automated, no skill is required for operation.

(4) Equipment costs are low because no special curved vessels are required.

[Brief explanation of the drawing]

1.2,3. Figure 4 is a front view of the combination filter; Figure 5 is an illustration of changes in the amount of light received by the combination filter due to differences in water surface conditions; Figure 6 is a measurement vehicle equipped with a measuring device. A side view showing a state in which
FIG. 7 is a front view thereof, FIG. 8 is a block diagram showing each component, and FIG. 2 is a three-dimensional view of the measuring device viewed diagonally from below. 1 is the floodlight, 2 is the road surface, Ro is the water surface, and 4 is nature. 5 is polarized light, 6 is a combination polarizing filter, 7 is a light receiver, 8 is a measurement wheel, 9 is a measurement device, 10 is a processing device, 11 is a light projector, 12 is a speedometer, 13 is an adjustment knob, 14 is a measurement 15 is a calculation unit, 16 is a recording unit, 17 is a display unit, 18 is a display window, 19 is a printer, 20 is a case, 21 is a glass window, 22 is a water spray nozzle, and 26 is a wiper.

Claims (1)

[Claims] It has a light projector 1 that is directed at a certain angle to the road surface, and a light receiver 7 that is installed on its reflection angle line, and a polarizing filter 6 is provided between the two directions, and the light is received by a photosensitive element in the light receiver Z. A road water level measuring device characterized in that a measuring section 14 for measuring the amount of water received is connected.