JPH0561598B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a road surface condition measuring method and measuring device for obtaining road surface information when, for example, the road surface is covered with snow or snow is falling. .

(Prior Art) Conventionally, during the winter season, it often snows in various regions such as the Tohoku region, the Hokuriku region, and the Hokkaido region, and snow accumulates on the road surface. In particular, snow gauges have been developed that measure the depth (height) of snow accumulated on road surfaces.

(Problem to be Solved by the Invention) By the way, the above-mentioned conventional snow gauge only measures how much snow has accumulated on the road surface. It was not possible to automatically and continuously determine whether the surface was melting snow, dirty snow like a shear bed, or melting snow or ice. Therefore, for example, if a car were to drive without knowing the road surface conditions, it would not be possible to prevent slips or traffic accidents from occurring.

In view of the above circumstances, the purpose of the present invention is to automatically and immediately know the road surface condition (road information or snowfall information) accurately, thereby enabling a method to measure road surface conditions to take appropriate measures. and to provide a measuring device thereof.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides data on the actual snow depth and amount of reflected light detected by the light wave snow gauge 7, and data on the amount of reflected light detected by the light wave snow gauge 9. Actual snowfall amount data detected by , actual outside temperature data detected by the outside air thermometer 13 , and actual road surface temperature data detected by the radiation thermometer 11 are respectively taken into the arithmetic processing/discrimination unit 109 . , in the arithmetic processing/discrimination unit 109, each of the detected detection values, a stacking depth setting value taken in advance, a plurality of reflected light amount setting values, a snowfall amount setting value, an outside temperature setting value, and a plurality of road surface temperatures. By comparing each with the set value and combining all the judgment results, it is possible to detect frozen road surface with no snowfall, shearbed-like road snow with no snowfall, shearbet-like road snow with snowfall, normal snowfall without snowfall, and snowfall. This method of measuring road surface conditions is characterized by obtaining seven types of road surface information: normal snowfall, no snowfall with the possibility of freezing, and normal road surface without snowfall.

The present invention also provides a lightwave snow gauge 7 that projects lightwaves from a lightwave transmitter toward the snow surface and receives reflected light from the snow surface with a lightwave receiver to detect stacking depth data and reflected light amount data; The number of snowflakes during snowfall,
A light wave snowfall meter 9 detects snowfall data by measuring the number of reflected lights from snowflakes per unit time, an outside air thermometer 13 that detects outside temperature data, and a radiation thermometer 11 that detects road surface temperature data. and the actual snow depth data, reflected light amount data, snowfall amount data, outside temperature data, and road surface temperature data detected by the light wave snow gauge 7, light wave snow gauge 9, outside air thermometer 13, and radiation thermometer 11. and a pre-loaded snow depth set value, multiple reflected light amount set values, snowfall amount set value, outside temperature set value, and multiple road surface temperature set values, and then combine all of the determination results. Accordingly, frozen road surface with no snowfall, shearbed-like road snow with no snowfall, shearbed-like road snow with snowfall, normal snowfall with no snowfall, normal snowfall with snowfall, no snowfall with the possibility of freezing, and normal road surface. A calculation processing/discrimination device 109 for obtaining seven types of road surface information including the absence of snow cover constitutes a road surface condition measuring device.

(Function) By employing the road surface condition measuring method and measuring device of the present invention, the light wave snow gauge 7 and the light wave snow gauge 9 detect snow depth data, reflected light amount data, and snowfall amount data, respectively. Also,
Outside air temperature data and road surface temperature data are detected by an outside air thermometer 13 and a radiation type thermometer 11. These detected snow depth data, reflected light amount data, snowfall amount data, outside temperature data, and road surface temperature data are taken into the calculation/discrimination device 109 and stored in advance as snow depth setting values and multiple reflected light amounts. The set value, snowfall amount set value, outside air temperature set value, and multiple road surface temperature set values are each subjected to comparison calculation processing and discrimination processing, and by combining all the judgment results, it is possible to determine whether the road surface is frozen with no snowfall or snowfall. Sheerbed-like road snow without snow, sherbet-like road snow with snowfall,
Seven kinds of road surface information, including normal snowfall with no snowfall, normal snowfall with snowfall, no snowfall with the possibility of road surface freezing, and normal road surface with no snowfall, can be obtained automatically, instantly, and accurately. By knowing the various types of road surface information that have been measured, a response suitable for the road surface condition can be taken.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Referring to FIG. 3, a measurement unit 5 as a road surface condition measuring device is attached to the upper part of the support post 1 erected on the ground GL via a support mounting bracket 3 at a downward angle (for example, relative to the support support 1). (approximately 20 degrees), and the measurement unit 6 is supported horizontally or slightly downward. The measuring section 5 includes a light wave snow gauge 7 as a snow gauge and a radiation thermometer 11 as a road surface thermometer, and the measuring section 6 includes a light wave snow gauge 9 as a snow gauge. Built-in. Furthermore, an outside air thermometer 13 is attached to the support column 1 at an appropriate height.

The light wave snow gauge 7 built into the measurement unit 5 measures the snowfall when snow falls to a certain height above the ground GL.
It measures snow depth (height). That is, the light wave snow gauge 7 projects light waves toward the snow surface from a light wave transmitter of a light wave transmitter/receiver whose details will be described later.
Measure the phase difference between the first received signal, which is the reflected light from the snow surface received by the light wave receiver of the light wave transmitter/receiver, and the second received signal, which is the light wave from the light wave signal device that is directly received by the light wave receiver. This method attempts to obtain the actual snow depth by determining the distance d between the light wave transceiver and the snow surface.

Now, let T be the time from when the light transmission signal is emitted from the light emitting element to when the received signal is obtained at the light receiving element, T = 2d/c (sec) However, d: Snow accumulation from the light emitting element and the light receiving element Distance to (m) c: Speed of light (≒) 3×10 ⁸ m/sec).

Therefore, by measuring the time T, the distance d can be found as d=T×c/2. but,
In reality, since the speed of light c is very high, the time T becomes very small, making it difficult to perform high-resolution measurements. The phase lags behind the received signal in proportion to the distance.

Since the modulation frequency of the light transmission signal is, for example, 15 MHz, the wavelength λ=C/15 MHz≈20 m.

Here, the distance d, the phase of the reflecting surface in the snow, and the phase of the light receiving position have a relationship as shown in FIG. 4.

For example, if the distance d from the light-emitting element and the light-receiving element to the reflective surface, which is a snow-covered surface, is 5 m, and when the phase of the light transmission position is 0°, the phase of the reflective surface is λ/4,
Since the phase on the surface of the light receiving element is λ/2 again,
There is a relationship between the distance d and the phase difference φ: d=λ/2×(φ/2π)m...(1) However, φ: radian, and the distance can be calculated by measuring the phase difference at the light receiving position. can be found.

When d>λ/2, that is, when d is 10 m or more, the phase returns to 0 again and becomes sawtooth as shown in FIG.

That is, d=λ/2×n×λ/2×(φ/
2π) However, n = 0, 1, 2,... This shows that the distance d and the phase difference φ are in a proportional relationship, and the distance d can be found by measuring the phase difference φ, but in this implementation In the example, this is performed when n=0.

When the distance d is measured, h=d cosθ,
The height of the snow surface is measured, and furthermore, the snow depth (height) is measured by H=H ₀ -h.

At the same time, the light wave snow gauge 7 also measures the amount of reflected light from the snow surface. The light wave snowfall gauge 9 built into the measurement unit 6 is optically adjusted and set so that the focal point of the transmitted and received light is placed horizontally or slightly downward, for example, at a position of about 3 m. The snowfall amount measured by the light wave snowfall meter 9 is obtained by counting the number of falling snowflakes at this location per unit time based on the number of reflected lights from the snowflakes.

Radiation type thermometer 11 built in the measurement section 5
The temperature of a surface substantially the same as the measurement surface of the light wave snow gauge 7 is measured using a pyroelectric infrared detection element.

Further, the outside air thermometer 13 measures the outside temperature using a normal thermometer.

A configuration block diagram for processing data detected by the light wave snow gauge 7, light wave snow gauge 9, radiation thermometer 11, and outside air thermometer 13 is shown in FIG.

In FIG. 1, the light wave transmitter/receiver 15 of the light wave snow gauge 7 is composed of a light wave transmitter 17 and a light wave receiver 19. The light wave transmitter 17 includes a light transmitting lens 21 consisting of an objective lens, a reflecting mirror 23 with a hole in the center, an optical attenuator 27 adjusted by a motor 25, and a light transmitting diode 29.
and a transmitting circuit 31.

The light wave receiver 19 also includes a light receiving lens 33 consisting of an objective lens, a reflecting mirror 35 having a hole in the center, a light receiving diode 37, and a receiving circuit 39.
It consists of etc. A shutter 43 rotated by a motor 41 is provided between the reflecting mirror 23 and the reflecting mirror 35.

The transmitting circuit 31 and the receiving circuit 39 are connected so that transmission and reception can be performed using local signals, and the transmitting circuit 31 and the receiving circuit 39 are connected to an arithmetic processing section 45. An interface section 47 is connected to this arithmetic processing section 45, and this interface section 47 has the following functions:
AC/DC converter 49, data output connector 5
1 are connected to each other. An input connector 53 is connected to the AC/DC converter 49.

With the above configuration, AC/
DC converter 49, interface section 47,
The transmitting circuit 31 and the receiving circuit 39 are activated through the arithmetic processing section 45. And the light transmitting diode 29
The light wave is sent to the light transmission lens 21 via the reflection mirror 23 and the optical attenuator 27. The light transmission signal sent to the light transmission lens 21 is projected toward the snow covered surface.

The reflected light reflected from the snow surface is collected by a light receiving lens 33, further reflected by a reflecting mirror 35, and received by a light receiving diode 37 as a first reception signal. Further, the light transmission signal from the light transmission diode 29 is reflected by the reflection mirror 23 and transmitted to the shutter 29.
The light is then reflected by a reflecting mirror 35 and received by a light receiving diode 37 as a second received signal with a phase difference from the first received signal. The first received signal and the second received signal are taken into the arithmetic processing section 45 via the receiving circuit 39. This arithmetic processing section 45
Then, the snow depth is calculated based on the above-mentioned equation (1), and is output as snow depth data from the data output connector 51 via the interface section 47.

The light wave transceiver 55 of the light wave snowfall gauge 9 is composed of a light wave transmitter 57 and a light wave receiver 59. The light wave transmitter 57 includes a light transmission lens 61 consisting of an objective lens, and a reflection mirror 6 with a hole in the center.
3, a light transmitting diode 65, a transmitting circuit 67, and the like. The light wave receiver 59 also includes a light receiving lens 69 consisting of an objective lens, and a reflecting mirror 7.
1, a light receiving diode 73, a receiving head amplifier 75, and the like.

A shutter 79 rotated by a motor 77 is provided between the reflecting mirror 63 and the reflecting mirror 71. The transmitting circuit 67 and the receiving head amplifier 75 are each connected to an arithmetic control section 81. The arithmetic control section 81 includes an AD converter 83, a data processing circuit 85, a motor controller 87, and the like.

The calculation control section 81 includes a monitor 89, a level meter 91, a data output connector 93, and an AC/
A DC converter 95 and the like are connected. this
An input connector 97 is connected to the AC/DC converter 95.

With the above configuration, the AC/
The transmitting circuit 67 and receiving head amplifier 75 are activated via the DC converter 95 and the arithmetic control section 81. The light wave is then sent to the light transmitting lens 61 by the light transmitting diode 65 via the reflecting mirror 63.
The light transmission signal sent to the light transmission lens 61 is projected toward the snowflakes.

The light reflected by the snowflakes is collected by a light receiving lens 69, further reflected by a reflecting mirror 71, and received by a light receiving diode 73 as a first reception signal. Further, the light transmission signal from the light transmission diode 65 is reflected by the reflection mirror 63, passes through a shutter 79, is reflected by the reflection mirror 71, and is sent to the light reception diode 73 as a second reception signal, which has a phase difference with the first reception signal. The light is also received. The first received signal and the second received signal are taken into the data processing circuit 85 of the calculation control section 81 via the reception head amplifier 75. The data processing circuit 85 calculates the amount of snowfall based on changes in the amount of reflected light, and outputs the data from the data output connector 93 as snowfall amount data.

The radiation thermometer 11 includes a light receiving lens 99 consisting of an objective lens, a detection sensor 101 consisting of a pyroelectric infrared detection element, and a reflecting mirror 103.
, head amplifier 105 , and data processing section 107
It consists of etc.

With the above configuration, radiant heat (infrared rays) from the snow surface
is directly received by the light receiving lens 99. The received light is detected by a detection sensor 101 as an infrared ray of a specific wavelength, and then passes through a head amplifier 105 to a data processing unit 10.
Sent to 7. The data processing unit 107 performs data processing based on the detected amount of infrared energy, and outputs the data as road surface temperature data.

Snow depth data and reflected light amount data detected by the snow gauge 7, snowfall amount data detected by the snow gauge 9, road surface temperature data detected by the radiation thermometer 11, and outside temperature detected by the outside air thermometer 13. The data is taken into the arithmetic processing and discrimination device 109. The arithmetic processing/discrimination unit 109 includes an arithmetic processing/discrimination unit 111 that performs arithmetic processing and discrimination based on the above data;
1, a power supply section 115 for operating this display 113 and the arithmetic processing/discrimination section 111, a relay/interface section 117, etc. It is configured.

With the above configuration, the arithmetic processing/discrimination unit 111
Now, the operation will be based on the flowchart shown in FIG. That is, in FIG.
In S1, set the snow depth, snowfall amount, outside temperature, radiant temperature, and reflected light amount as initial values to H, M, T, t,
Set to B.

In step S2, it is determined whether the outside temperature T is T<a, and if T<a, in step S3, the snowfall amount M is
It is determined whether or not =0.
If M=0, proceed to step S4 and set the snow depth H.
A determination is made as to whether H is H=0, and H is H>0.
If so, proceed to step S5. In step S5, it is determined whether the radiation temperature t is t<g, and if t<g, the step S5 is performed.
In step S6, f(t, i) [where i: amount of reflected light] is calculated, and in step S7, information on a frozen road surface (no snowfall) is obtained as road surface condition A.

If it is determined in step S4 that the snow depth H is H>0, the process does not proceed to step S5, and in step S8 it is determined whether the amount of reflected light B satisfies B<f. If B>f, step S6
and processed as described above.

If B<f in step S8, step S9
The process proceeds to step S10, where f(t, i) is calculated, and information about a shearbed-like road surface (no snowfall) is obtained as road surface condition B at step S10.

In step S3, if M>0,
The process proceeds to step S11, where the snow depth H is determined, and if H>0, the process proceeds to step S12. In step S12, it is determined whether the radiation temperature t is t<d, and if t<d,
And the amount of reflected light B in step S8 satisfies B<f
In this case, f(t, i) is calculated in step S13, and information on normal snowfall (no snowfall) is obtained as the road surface condition C in step S14.

In step S12, if t<d,
The process also proceeds to step S15, where f(t, i) is calculated, and information about normal snowfall (snowfall) is obtained as the road surface condition D at step S16.

If the snow depth H is H>0 in step S11, the process advances to step S12 and also to step S17. In step S17, the amount of reflected light B
It is determined whether B<e. If B>e, step S13 or step
The process advances to S15 and is processed in the manner described above.

If B<e is determined in step S17, and t>d in step S12, an arithmetic process of f(t, i) is performed in step S18, and
In step S19, information on shear bed-like snow accumulation (snowfall) is obtained as the road surface condition E.

If T>a in step S2, step S20
It is determined whether the snow depth H is H=0, and if H>0, the step
The process proceeds to step S5 or step S8 and is processed as described above.

If H=0 in step S20 and H=0 in step S4 and step S11, the process advances to step S21 or step S22.

In step S21, it is determined whether the radiation temperature t is greater than b, and step S21 is performed.
In S22, it is determined whether the amount of reflected light B satisfies B<C.

t<b in step S21, B> in step S22
If it is C, the process advances to step S23 and f(t,
The arithmetic processing in i) is performed, and in step S24, information is obtained as the road surface condition F, indicating that there is no snowfall and there is a possibility of the road surface freezing.

If t>b in step S21 and B<C in step S22, proceed to step 25, and f
The arithmetic processing of (t, i) is performed, and step
In S26, information on the road surface condition G, with no snow and normal road surface, is obtained.

In this way, the snow gauge 7 measures the snow depth H and the amount of reflected light B, the snow gauge 9 measures the snowfall amount M, and the radiation thermometer 1
1 is the radiation temperature t, outside air thermometer 13 is the outside temperature T,
By detecting each, as mentioned above,
Various road surface information from road surface condition A to road surface condition G can be obtained automatically, instantly, and accurately. Therefore, by knowing these various types of road surface information, it is possible to take appropriate measures to suit the road surface conditions.

Note that this invention is not limited to the embodiments described above, and can be implemented in other forms by making appropriate changes.

[Effects of the Invention] As can be understood from the above description of the embodiments, according to the present invention, the light wave snow gauge 7, the light wave snow gauge 9, the radiation thermometer 11, and the outside air thermometer 1
3, snow depth data, snowfall amount data, road surface temperature data, and outside temperature data are respectively detected, and these data are taken into the arithmetic processing/discrimination device 109.
By performing arithmetic processing and discrimination processing using each set value set in advance, and combining all the judgment results, it is possible to determine whether the road surface is frozen with no snowfall, shearbet-like road snow with snowfall, or shearbet-like road snow with snowfall. Snowy roads, normal snowfall with no snowfall, normal snowfall with snowfall, no snowfall with the possibility of freezing, and 7 with no snowfall on normal roads.
Street surface information can be obtained automatically, instantly, and accurately. Therefore, by knowing these various kinds of road surface information, it is possible to take appropriate measures depending on the road surface information. In other words, it contributes to predicting road surface conditions and determining snow removal methods during the winter.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a road surface condition measuring device which is the main part of this invention, Fig. 2 is a flowchart for obtaining various road surface conditions, and Fig. 3 is an example of an implementation in which the road surface condition measuring device is installed. The side view of the example, Figure 4, is the distance d between the light wave transceiver and the snow surface.
FIG. 5 is a diagram showing the relationship between distance d and phase φ, and FIG. 5 is a diagram showing the relationship between distance d and phase φ. DESCRIPTION OF SYMBOLS 1... Strut, 5... Measuring unit, 7... Light wave snow gauge (snow gauge), 9... Light wave snow gauge (snow gauge), 11...
...Radiation type thermometer (road surface thermometer), 13...Outside air thermometer, 109...Arithmetic processing/discrimination device.

Claims (1)

[Claims] 1. Actual snow depth data and reflected light amount data detected by the light wave snow gauge 7, actual snowfall data detected by the light wave snow gauge 9, and actual snowfall data detected by the outside air thermometer 13. The outside temperature data and the actual road surface temperature data detected by the radiation thermometer 11 are respectively taken into the arithmetic processing/discrimination unit 109, and the arithmetic processing/discrimination unit 109 combines the detected values and the actual road surface temperature data detected by the radiation thermometer 11. By comparing and judging the imported snow depth setting value, multiple reflected light intensity setting values, snowfall amount setting value, outside temperature setting value, and multiple road surface temperature setting values, and combining all the judgment results, snowfall No frozen road surface, shear bed snow with no snowfall, shear bed snow with snowfall, normal snowfall with no snowfall, normal snowfall with snowfall, no snowfall with possibility of road snow freezing, no normal road snowfall A road surface condition measuring method characterized by obtaining seven types of road surface information. 2. A light wave snow gauge 7 that projects light waves from a light wave transmitter toward the snow surface and receives reflected light from the snow surface with a light wave receiver to detect stacking depth data and reflected light amount data, and a light wave snow gauge 7 that detects snow flakes during snowfall. a light wave type snowfall meter 9 that detects snowfall data by measuring the number of reflected light from snowflakes per unit time; an outside air thermometer 13 that detects outside temperature data; and a radiation type that detects road surface temperature data. Actual snow depth data, reflected light amount data, snowfall amount data, outside temperature data detected by the thermometer 11, the light wave snow gauge 7, the light wave snow gauge 9, the outside air thermometer 13, and the radiation thermometer 11, The road surface temperature data is compared with the pre-loaded snow depth set value, multiple reflected light intensity set values, snowfall amount set value, outside temperature set value, and multiple road surface temperature set values, and all judgment results are evaluated. By combining, road surface freezing with no snowfall, shearbed-like road snow with no snowfall, shearbet-like road snow with snowfall, normal snowfall with no snowfall, normal snowfall with snowfall, and no snowfall with the possibility of road snow freezing. , arithmetic processing/discrimination device 10 for obtaining seven types of road surface information including normal road surface and no snow accumulation.
9. A road surface condition measuring device comprising: