| 摘要 |
PURPOSE:To enhance the discrimination accuracy of the state of a road surface, by discriminating the state of the road surface of frequency distribution calculated by classifying the intensity of a receiving wave into three large and small sections by receiving the reflected wave of an ultrasonic wave repeatedly transmitted toward the road surface. CONSTITUTION:The road surface state detection apparatus 1 mounted to the underside of a car body is constituted so that ultrasonic waves are emitted to a road surface W at a predetermined cycle from an oscillation apparatus 4 and a transmitting microphone 3 under the control of a control apparatus 2. Ultrasonic waves reflected from the road surface W are received by a receiving microphone 5 and a receiving apparatus 6 to be inputted to the control apparatus 2. The control apparatus 2 classifies the intensities of the receiving waves into three large and small sections on the basis of a predetermined standard to calculate the frequency distribution of each intensity. The reflection intensities respectively show characteristic distributions with respect to a fresh snow road, a pressed snow road, a frozen road, a paved road inferior to a paving degree, a worn-out rough road surface and a well-paved road. By this method, the state of the road surface can be accurately judged and safe driving can be performed.
|
