| 摘要 |
<p>PURPOSE:To generate the warning of freezing accurately by providing an infrared-ray detecting means which detects infrared rays from the road surface right under a vehicle and generates an infrared-ray signal, and a means which receives the signal from the detecting means and judges the freezing state of the road surface. CONSTITUTION:The infrared-ray sensor 1 is provided to the lower part of the vehicle and detects infrared rays from the road surface right under the vehicle. Further, an outside air temperature sensor 2 detects the temperature of the air outside of the vehicle. An A/D converter 3 converts the detection signals from the infrared-ray sensor 1 and outside air temperature sensor 2 into digital signals. When the outside air temperature is lower than 10 deg.C, infrared-ray data is inputted in a step 103 from the infrared-ray sensor 1 through the A/D converter 3, and a decision whether the road surface is at the freezing temperature or not is made in a step 104. Consequently, the road temperature is detected accurately under less influence of the sunshine.</p> |
