JP2826753B2 - Road surface measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road surface measuring device for measuring snow cover, debris flow, and the like on a road surface.

[Conventional technology]

An optical wave distance meter is used as an unmanned snow gauge for road management. The lightwave type distance meter emits an optical pulse wave toward a target surface, receives reflected light, detects the time required for reciprocation based on the pulse phase difference, and uses a known principle to determine the distance to the target. It is based on civil engineering surveys. When applied to a snow gauge, the range finder is mounted on a pole facing the road surface, and the snow height on the road surface is determined with an accuracy of 1 cm or less based on the measured distance to the snow surface.

Many such snow gauges are installed along the road, and each measurement data is transmitted to the management center by wire or wirelessly, and is used for road management such as whether or not traffic is required, whether tire chains are required, and whether snow is removed. Used as data.

In order to monitor the condition of the road surface (snow and irregularities), ITV cameras were placed along the road, and the road manager at the centralized monitoring center judged the condition by looking at the monitor.

[Problems to be solved by the invention]

The conventional snow gauge has a problem that a puddle due to rainfall, a foreign substance (a load falling object), a falling rock, or the like is erroneously detected as snow.

With ITV cameras, it was not easy to determine whether the surface of the snow had melted like a sherbet or frozen like an ice burn. For this reason, it has been difficult to properly perform road management such as closing roads, displaying and checking the installation of chains, and spraying a snow melting agent. Another disadvantage is that ITV cameras cannot be monitored at night.

In view of this problem, an object of the present invention is to make it possible to easily and reliably determine the state of a measurement surface and to configure an advanced monitoring and management system.

[Means for solving the problem]

The road surface measuring device of the present invention includes a distance meter that measures a distance from above to a measurement point on a road by a time difference between a radiation wave and a reflected wave, a radiation thermometer that measures a surface temperature of the measurement point, and the distance meter. And a deflection mechanism for deflecting the objective axis of the radiation thermometer to form a row of measurement points along the road surface, and to determine unevenness of the road surface based on distance measurement data, surface temperature data, and deflection angle data for each measurement point. And a display device for displaying a temperature distribution along the cross section and the cross section shown.

[Action]

The depth of snow on the road surface and the like are calculated based on the distance measurement value and the deflection angle, and the horizontal position and snow depth data of many measurement points are plotted to create a snow cross section. The distribution of the surface temperature is displayed along the cross-sectional view by, for example, color coding corresponding to the temperature.

The road surface condition is determined based on the snow depth, surface unevenness, and temperature display by the cross-section display, which is useful for road and traffic management.

〔Example〕

FIG. 1 shows a system diagram of a road monitoring device to which the present invention is applied.

The sensor unit 1 integrates an optical distance meter 2 and a radiation thermometer 3 and is installed toward a road surface 4 at a height of about 6 m. In addition, the distance meter 2 and the thermometer 3
Each is directed to measure the distance to the same point on the road surface 4 and the surface temperature.

The lightwave distance meter 2 transmits the pulsed light from the light emitting element 20 to the lens 21.
Through the lens to the target surface, and reflects the reflected light from the target surface to the lens.
It focused light to be detected by the light receiving element 23 at 22, and measures the distance to the target surface based on the phase difference between the sending pulse light L _T and the light receiving pulse light L _R in the measurement circuit.

The radiation thermometer 3 detects infrared radiation L ₁ from the target surface and obtains data converted into surface temperature based on the radiation side of the plank. The radiation incident through the protective filter 31 is reflected by the concave mirror 32. The light is condensed, and enters a detector 35 such as a pyroelectric detector or a semiconductor infrared detector via a chopper 33 (electrostrictive vibrator) and a spectral sensitivity correction feeder 34. (The ratio of the measurement object to the body emissivity) and converts the data into temperature data.

The lightwave distance meter 2 and the radiation thermometer 3 each incorporate a calculation circuit (microcomputer) for calculating the distance (height) and the surface temperature based on the measurement signal, and each distance data L and temperature data T
Is transmitted to the data processing device 10 of the road management center through the interface circuit 7 and the cable 8.

The processing result of the data processing device 10 is displayed on the display 11.

FIG. 2 is a layout view of a sensor unit 1 having a built-in optical distance meter 2 and a radiation thermometer 3, and FIG.

The sensor unit 1 is mounted on a support 14 having a height of about 6 m. The unit 13 is rotatably supported by a pair of support arms 16a and 16b fixed inside the outer casing 15 via a support shaft 17, and the optical axis K of the lightwave distance meter 2 and the radiation thermometer 3 is Is rotatable in a vertical plane so as to traverse. The rotation of the optical axis K is performed by a motor 18 attached to a support shaft 17, and the tilt angle θ of the optical axis K with respect to the vertical line is measured by a rotary encoder 19 attached to the support shaft 17. The output data of the rotary encoder 19 is also transmitted to the data processing device 10 via the interface circuit 7 and the cable 8. The processing device 10 calculates the snow depth D on the road surface 4 based on the height H of the distance meter from the reference plane R, the distance measurement value L, and the optical axis angle θ.

D = H−L cos θ (1) The data of the snow depth D is acquired at a number of points on a straight line crossing the road surface 4 while continuously or intermittently moving the optical axis K of the sensor unit 1. The moving speed of the optical axis K is, for example, 10 cm / sec. Assuming that the column 14 is the origin, the horizontal distance X to each measurement point is X = L sin θ (2).

At the same time, surface temperature data T is obtained at each measurement point.

Each data of the snow depth D and the surface temperature T with respect to the horizontal distance X from the origin is converted into graphic data in the data processing device 10 and is displayed on the display 11 in the form of a cross-sectional view across the road as shown in FIG. Is displayed. This display has a line of the road surface 4 obtained from the measured data and a line indicating the surface of the snow 5. Cross sections 5 a, 5 b,... Of the snow 5 on the road 4 are color-coded based on the surface temperature data T. Is displayed. For example, 0 ° C is red, -3 ° C is blue, +3
℃ is green.

By looking at the road cross-sectional view on the display 11 in this way, it is possible to know the unevenness of the snow surface, and the snow 5 is frozen in an ice-burn state by the color-coded display along with the unevenness ( Low temperature with severe irregularities)
It is dissolved in a sherbet shape (the unevenness is gentle and around 0 °) or completely dissolved to form a puddle. (Flat and hot). Also, when there is a load drop on the road surface, it can be discriminated from the cross-sectional shape and the temperature display.

Since the measurement of the distance and the surface temperature for obtaining the above-described cross-section display is performed using infrared light, road surface monitoring can be performed without any trouble even at night.

The road management center determines the road maintenance by looking at the display 11. For example, if the amount of snow is relatively small and the surface is sherbet-like, a snow melting agent is sprayed. If the amount of snow is large, the road is closed and snow removal is performed. If the surface is ice-burn,
A lightning display with a tire chain attached will be given to passing vehicles, and a check for chain attachment will be made.

A thermometer 13 and a barometer 13 are attached to the sensor unit 1.
Is transmitted to Since these data are displayed on the screen of the display 11 by numbers, it is possible to predict the state change of the snow cover 5 by combining the cross-section display and these data. For example, if the temperature is low even if the surface is sherbet-like, it can be predicted that the road surface will gradually freeze.

The road monitoring device shown in FIG. 1 can be applied to a volcano observation device and a debris flow observation device. Also in this case, the cross sections of the lava flow and the debris flow are displayed in different colors according to the temperature.

In FIG. 3, if the motor 18 is a pulse motor, the rotary encoder 19 is unnecessary, and if the drive pulses of the pulse motor are counted, the deflection angle θ can be determined by the data processing device.
10 can be calculated.

〔The invention's effect〕

As described above, the present invention is capable of monitoring a substance on a road surface (for example, snow cover) by displaying a cross section and displaying a temperature distribution along the cross section, and the degree of snow cover and its state (freezing, sherbet shape) can be easily displayed. And an advanced road management system can be configured.

Further, since the distance meter and the radiation thermometer do not use visible light, measurement data can be obtained regardless of day or night.

[Brief description of the drawings]

FIG. 1 is a system diagram of a road monitoring system to which the present invention is applied,
FIG. 2 is a diagram showing the arrangement of the sensor units and a cross section of the road, and FIG. 3 is a cross-sectional view of the sensor unit. In addition, in the code | symbol used for drawing, 1 ... Sensor unit 2 ... Electric wave distance meter 3 ... Radiation thermometer 4 ... Road surface 5 ... Snow cover 10 ... Data processing apparatus 11 ... Display 18 ... Motor 19 ... It is a rotary encoder.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01C 7/00-7/02 G01W 1/00

Claims (2)

(57) [Claims] A distance meter for measuring a distance from above to a measurement point on a road by a time difference between a radiation wave and a reflected wave; a radiation thermometer for measuring a surface temperature of the measurement point; A deflection mechanism that deflects the object axis of the meter to form a row of measurement points along the road surface, and a cross-section display that shows the unevenness of the road surface based on the distance measurement data, surface temperature data, and deflection angle data for each measurement point And a display device for displaying a temperature distribution along a cross section. 2. The apparatus according to claim 1, wherein each measurement data of said rangefinder and radiation thermometer is remotely transmitted to a central data processing device, and said display device is attached to said central data processing device. Item road surface measurement device.