Road surface sensor and monitoring control method for road surface

• US 6,979,146 B2
• Filed: 08/24/2004
• Issued: 12/27/2005
• Est. Priority Date: 08/25/2003
• Status: Expired due to Fees

• Current Assignee: Japan Highway Public Corp. (Government of Japan), Yamada Technica Corporation
• Original Assignee: Japan Highway Public Corp. (Government of Japan), Yamada Technic Corporation
• Inventors: Goto, Makoto, Yamamoto, Kouji, Yamada, Tadayuki
• Primary Examiner(s): Will, Thomas B.
• Assistant Examiner(s): Addie, Raymond W
• Application Number:
  US10/923,800
• Publication Number:
  US 20050047864A1
• Time in Patent Office: 490 Days
• Field of Search: 404/71, 404/77, 404/79
• US Class Current: 404/71
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F
• CPC Class Codes: G08B 19/02 Alarm responsive to formation or anticipated formation of ice

Abstract

In order to melt snow and prevent freezing without consuming energy wastefully and to monitor a road surface state remotely, a road surface sensor includes: a rotating stand provided so as to be reciprocatingly rotatable upward on the road surface; a snow-melting/freezing heat quantity measurement dummy road surface having an electric heater buried therein and to use as a reference road surface for heat quantity measurement to derive a melting heat quantity for snow falling on the surface and a heat quantity required for freezing prevention; a reference light irradiating/reflected light receiving device that is attached so as to be rotatable with the rotating stand; a space reflected light receiving device; a non-contact road temperature measuring device; a non-contact snow cover depth measuring device; a road surface image pickup device; and a moisture sensor. The reference light irradiating/reflected light receiving device includes a reference light irradiating device for irradiating reference light and a reflected light receiving device for receiving reflected light of the reference light from the road surface, and the reflected light receiving device separates and receives only reflected light of the reference light out of the reflected light from the road surface.

Claims

1. A road surface sensor for performing automatic control for road snow-melting by measuring a snowfall and an amount of freezing as a heat quantity required for snow-melting and a heat quantity required for freezing prevention in a unit time period, measuring a state of distribution of drying, wetting, snow cover, snow cover depth, and temperature on a road surface transversely in a non-contact manner, and combining the measured heat quantities and the state of road surface, the road surface sensor comprising:

a rotating stand provided so as to be reciprocatingly rotatable upward on the road surface;

a snow-melting/freezing heat quantity measurement dummy road surface having an electric heater buried therein and to be used as a reference road surface for heat quantity measurement to derive a melting heat quantity for snow falling on the surface and a heat quantity required for freezing prevention;

a group of sensors attached to the rotating stand so as to be rotatable together, the sensors consisting of;

a reference light irradiating/reflected light receiving device;

a space reflected light receiving device;

a non-contact road temperature measuring device;

a non-contact snow cover depth measuring device;

a road surface image pickup device; and

a moisture sensor, wherein

the reference light irradiating/reflected light receiving device includes a reference light irradiating device for irradiating reference light and a reflected light receiving device for receiving the reflected light of the reference light from the road surface, and the reflected light receiving device separates and receives only reflected light of the reference light out of the reflected light from the road surface.

2. A road surface sensor according to claim 1, wherein the reference light irradiating device includes four sets of irradiation sources, each set having a condensing type high-intensity light-emitting diode combined with a condensing lens to irradiate reference light on the road surface to which high-frequency modulation is applied, and the reflected light receiving device includes a condensing type phototransistor which is sensitive to same wavelength as a red wavelength of the reference irradiated light, and a lens for condensing reflected light on the light receiving device.

3. A monitoring control method for performing automatic control for road snow-melting in a remote location by measuring a snowfall and an amount of freezing as a heat quantity required for snow-melting and a heat quantity required for freezing prevention in a unit time period, measuring a state of distribution of drying, wetting, snow cover, snow cover depth, and temperature on a road surface transversely in a non-contact manner with a road surface sensor, and combining the measured heat quantities and the state of road surface, wherein the road surface sensor comprises:

a rotating stand provided so as to be reciprocatingly rotatable upward on the road surface;

a snow-melting/freezing heat quantity measurement dummy road surface having an electric heater buried therein and to be used as a reference road surface for heat quantity measurement to derive a melting heat quantity for snow falling on the surface and a heat quantity required for freezing prevention;

a group of sensors attached to the rotating stand so as to be rotatable together, the sensors consisting of;

a reference light irradiating/reflected light receiving device including a reference light irradiating device for irradiating reference light and a reflected light receiving device for receiving the reflected light of the reference light from the road surface, and the reflected light receiving device separates and receives only reflected light of the reference light out of the reflected light from the road surface;

a space reflected light receiving device;

a non-contact road temperature measuring device;

a non-contact snow cover depth measuring device;

a road surface image pickup device; and

a moisture sensor; and

a signal converter to change values measured by the respective sensors to signals, and

the road surface sensor performs snow-melting control by combining respective measurement results, transmits a road surface image for confirming the information on the measurement results and a snot-melting state as images, and receives an operation stop signal from an information receiving side.