JP2000346958A - Road surface condition estimation method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make accurately graspable the condition of a road surface by estimating the amount of insolation that the road surface receives according to the position of a structure or the like for shielding the road surface from a solar heat and the position of the sun. SOLUTION: When the insolation from the sun 21 is shielded by a building 22, a shade 24 is generated on a road surface 23. The position and area of the shade 24 on a target road are determined from solar position 25, the height 26 of the building 22, the width 27, the depth 28, and the distance 29 of the building 22 from the road; and the solar position 25 is determined by the latitude, longitude, and the day and time of the solar position 25. By measuring the latitude and longitude of the building 22, the height 26, the width 27, the depth 28 of the building 22, and distance 29 of the building 22 from the road in advance and storing them in a database 10; the shade 24 being formed at arbitrary time can be obtained. By setting the ratio of the amount of insolation of sunshine to that of the shade 24 to the insolation shielding rate, and creating the relationship between the solar position 25 and the insolation shielding rate in advance, the amount of insolation in the shade 24 can be obtained, thus obtaining the amount of insolation at arbitrary time on an arbitrary road surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for estimating road surface conditions based on weather information.
In particular, the present invention relates to a road surface condition estimation method and device capable of correctly estimating the road surface condition even when there are buildings around the road.

[0002]

2. Description of the Related Art As a system for estimating a road surface condition on a road, a system using weather information from a weather sensor is known. As shown in FIG. 4, a conventional road surface condition estimation system includes weather sensors such as a thermometer 2, a rain gauge 3, and a pyranometer 4 installed near a target road 1, and these weather sensors 2 and 3. , 4 via a signal line 7, an information collecting device 9 for receiving the measurement data, a road condition determination device 11 for determining a road condition based on the received measurement data, And a display 12 for displaying the determination result.

[0003] The road surface condition determination device 11 calculates the balance of heat flowing into and out of the road surface based on measurement data of temperature, rainfall, and solar radiation, as well as the relational expression between precipitation and water film thickness, snowfall and snowfall thickness. The condition of dry / wet / water film / snow / freeze on the road surface is determined by using a relational expression, a freezing determination algorithm or the like for determining freezing from the road surface temperature and the road surface wetness.

[0004]

When there is a building or a natural object around the road (hereinafter referred to as a building), this building serves as a shield that shields the road surface from the sun, so that solar radiation on the road surface is obstructed. Or the heat (infrared rays) emitted by the building is absorbed by the road surface. However, in the related art, since special weather information such as obstruction of solar radiation and radiant heat is not taken into consideration, the road surface condition may not be correctly estimated.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a road surface condition estimation method and device capable of correctly estimating the road surface condition even when there are buildings around the road.

[0006]

According to a first aspect of the present invention, there is provided a method of estimating a state of a road surface by calculating a balance of heat entering and exiting a road surface from weather information. The amount of solar radiation received on the road surface is estimated from the position of a shield such as a building that shields the road surface from the sun and the position of the sun.

The apparatus calculates the balance of heat flowing into and out of a road surface from weather information such as measurement data measured by a thermometer, a rain gauge, and a pyranometer, and calculates a dry / wet / water film / snow / freeze on the road surface. In the device for estimating the situation such as
A shield information unit that previously sets positional information of a shield such as a building that shields the road surface from the sun; a sun position calculating unit that calculates a position of the sun from a position on the earth of the road surface and the date and time; A solar radiation amount estimating means for estimating the amount of solar radiation received on the road surface from the position of an object and the position of the sun.

A second method of the present invention is a method for estimating the condition of the road surface by calculating the balance of heat flowing into and out of the road surface from weather information, the method comprising estimating a radiation object such as a building that radiates infrared rays to the road surface. The amount of infrared rays received on the road surface is estimated from the surface temperature and the distance from the radiant to the road surface.

The temperature of a simulated material that simulates the radiant may be measured and used as the surface temperature of the radiant.

The apparatus calculates the balance of heat flowing into and out of a road surface from weather information such as measurement data measured by a thermometer, a rain gauge, and a pyranometer, and calculates the balance of heat on the road surface to dry, wet, water film, snow and freeze. In the device for estimating the situation such as
Radiation temperature measuring means for measuring the surface temperature of a radiant such as a building that radiates infrared rays to the road surface, radiant information means for setting a distance from the radiant to the road surface in advance, and the surface temperature of the radiant An infrared ray amount estimating means for estimating an infrared ray amount received by the road surface from a distance from the radiant to the road surface.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, a road surface condition estimating system according to the present invention includes a weather sensor such as a thermometer 2, a rain gauge 3, and a pyranometer 4 installed near a target road 1;
A simulated material 5 made of a material having a radiation characteristic equivalent to that of a building (not shown) and placed in a shaded position and a sunlit position, and the temperature of the simulated material 5 is measured as the temperature of the building. A temperature sensor (radiation temperature measuring means) 6, a signal transmission device 8 for transmitting measurement data of these weather sensors 2, 3, 4, 6 via a signal line 7, and an information collecting device 9 for receiving the measurement data. , A database recording location data of buildings (shielding information means and radiant information means) 1
0, a road surface condition determining device (a solar position calculating device, a solar radiation amount estimating device, and an infrared amount estimating device) 11 for executing a road surface condition estimating program according to the road surface condition estimating method of the present invention to determine a road surface condition; And a display unit 12 for displaying.

The road surface condition judging device 11 includes an information collecting device 9
And the position data of the database 10 are read, and the balance of heat entering and exiting the road surface is calculated from weather information obtained by adding the amount of solar radiation to the road surface and the amount of infrared rays to the conventional measurement data of temperature, rainfall, and solar radiation. , The relational expression between precipitation and water film thickness, the relational expression between snowfall and snow thickness, and the use of a freezing determination algorithm to determine freezing from road surface temperature and road surface wetness, etc. Judgment of conditions such as snow and freezing.

First, the operation of estimating the amount of solar radiation will be described.

FIG. 2 shows a model of a shade by a building.
When the solar radiation from the sun 21 is blocked by the building 22, a shade 24 is generated on the road surface 23. The position and area of the shade 24 on the target road include the position of the sun (for example, a solar altitude angle) 25 viewed from the ground, the height 26 of the building 22, and the width 2
7, determined by depth 28 and distance 29 of the building from the road. Among them, the sun position 25 can be obtained from the position (latitude / longitude) of the target road on the earth and the date and time. Therefore, the building 22 and the position of the target road on the earth, the building 2
If the height 26, width 27, depth 28, distance 29 of the building from the road, and the like are measured in advance and stored in the database 10, the shade 24 generated at an arbitrary time can be calculated. it can.

The ratio of the amount of sunlight in the sun and the amount of sunlight in the shade 24 is defined as the solar shading rate. If a relational expression between the sun position 25 and the solar shading rate is created in advance, the amount of solar radiation in the shade 24 can be obtained from this relational expression.

Thus, the amount of solar radiation at an arbitrary time on an arbitrary road surface including the shade 24 can be obtained.

Next, the operation of estimating the amount of infrared rays will be described.

FIG. 3 shows the relationship between the distance from the building to the estimation target location and the amount of infrared rays received by the estimation target location. Assuming that the amount of infrared radiation emitted by the building is constant, the amount of infrared radiation received at the estimation target location is large if the estimation target location is close to the building, and the infrared radiation received at the estimation target location if the estimation target location is far from the building The quantity is small. If the relational expression representing the relation of FIG. 3 is created in advance, and if the distance from the building to the estimation target location and the amount of infrared radiation emitted by the building are known, the relational expression is used at the estimation target location. The amount of infrared radiation that can be obtained.

The amount of infrared radiation emitted by a building depends on the surface temperature of the building. The surface temperature of the building may be measured directly from the building, but here, a plurality of simulation materials composed of the same material as the building are installed, and the temperature of the simulation material in the shade and in the sun is measured. The surface temperature of the building when the building is in the shade and the surface temperature of the building when the building is in the sun.

Thus, the amount of infrared rays that can be received on an arbitrary road surface can be obtained using the distance from the building and the temperature of the simulation material.

As described above, the road surface condition estimation system of FIG. 1 takes into account not only the conventionally measured temperature, rainfall, and solar radiation, but also the heat balance taking into account the amount of solar radiation and the amount of infrared radiation that the road surface receives under the influence of the building. Is calculated, so that the road surface condition can be correctly estimated not only when there is no building around the road but also when there is a building.

The road surface condition estimating system according to the present invention can use not only data measured by a weather sensor but also weather data provided by a public weather station, and the road surface condition of a road laid in a real environment. The road surface condition can be accurately estimated throughout the year.

The weather data of the entire target road can be obtained by three-dimensional spline interpolation of weather data from a weather sensor or a public weather station. By using such weather data, it is possible to grasp not only the road surface condition near the place where the weather sensor is installed, but also the road surface condition of the entire length of the road.

[0025]

The present invention exhibits the following excellent effects.

(1) Since the amount of solar radiation and the amount of infrared rays received on the road surface due to the influence of the building are used for estimating the road surface condition, the road surface condition can be correctly estimated even when there is a building around the road.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a road surface condition estimation system according to an embodiment of the present invention.

FIG. 2 is a model diagram of a shade by a building.

FIG. 3 is a relationship diagram between a distance and an amount of infrared rays.

FIG. 4 is a configuration diagram of a conventional road surface condition estimation system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Road 2 Thermometer 3 Rain gauge 4 Pyranometer 5 Simulated material 6 Temperature sensor (radiation temperature measurement means) 10 Database (shield information means and radiant information information means) 11 Road surface condition determination device (sun position calculation means, solar radiation estimation Means and Infrared Amount Estimating Means) 21 Sun 22 Building 23 Road surface 24 Shade

Claims (5)

[Claims] 1. A method for estimating the condition of a road surface by calculating the balance of heat flowing into and out of a road surface from weather information, wherein the position of a shield such as a building that shields the road surface from the sun and the position of the sun are determined. A method for estimating a road surface condition, comprising estimating an amount of solar radiation received by the road surface. 2. The balance of heat flowing into and out of a road surface is calculated from weather information such as measurement data measured by a thermometer, a rain gauge, and a pyranometer to calculate the balance of dry / wet / water film / snow / freezing on the road surface. In a device for estimating a situation, a shield information unit that previously sets position information of a shield such as a building that shields the road surface from the sun, and a sun that calculates the position of the sun from the global position and the date and time of the road surface A road surface condition estimating apparatus comprising: a position calculating unit; and a solar radiation amount estimating unit that estimates a solar radiation amount received by the road surface from the position of the shield and the position of the sun. 3. A method for estimating the state of the road surface by calculating the balance of heat flowing into and out of the road surface from weather information, wherein the surface temperature of a radiant such as a building radiating infrared rays to the road surface and the radiant A method of estimating a road surface condition, comprising estimating an infrared ray amount received by the road surface from a distance to the road surface. 4. The road surface condition estimating method according to claim 3, wherein a temperature of a simulated material simulating the radiant is measured and used as a surface temperature of the radiant. 5. A balance of heat flowing into and out of the road surface is calculated from weather information such as measurement data measured by a thermometer, a rain gauge, and a pyranometer, and the balance of dry / wet / water film / snow / freezing on the road surface is calculated. In the device for estimating the situation, radiation temperature measuring means for measuring the surface temperature of a radiant such as a building that radiates infrared rays to the road surface, and radiant information information means that previously set the distance from the radiant to the road surface A road surface condition estimating device, comprising: infrared ray amount estimating means for estimating an infrared ray amount received by the road surface from a surface temperature of the radiated object and a distance from the radiated object to the road surface.