Research On Freeway Running Under Heavy Fog Based On Infrared-induced

In order to achieve highway running under heavy fog, a new method of guiding the vehicle based on IR-induced is proposed, according to the infrared light's higher ability of penetrating heavy fog than visible light. In the method, the both sides of road are paved with infrared-induced signs, and vehicle location and direction are archived from infrared-induced signs.In the overall research, 70~80℃was identified as infrared-induced signs'operating temperature after analyzing the infrared transmission characteristics in the atmosphere and heavy fog, and vehicle's temperature. According to Johnson criteria, infrared-induced signs'size and layout in the linear sections and curved sections are designed. And then, infrared-induced system in accordance with the proportion of one-twentieth is carried out in fog chamber.In the infrared-induced extraction, in order to reduce the time of infrared-induced signs extracted, the infrared-induced ROI area is introduced. According to the adaptive segmentation method's bad performance of the long-distance infrared-induced signs'extraction, it is proposed that a method based on two-step to extract the infrared-induced sign. First, the large infrared-induced signs are extracted by its mean and variance, and the long-distance region is calculated with the close-distance infrared signs'location. In order to improve position accuracy of infrared-induced sign, the single infrared-induced region is reextracted. And then, the method use local area variance to erase background section in the long-distance area, and threshold the long-distance area by gray value of its edge. The results show that the method performs well in extracting the long-distance infrared-induced signs.In extracting the position and orientation of vehicle, the coordinate system associated with the vehicle and transformation relations are set. The parameters are extracted based on the shadow points when vehicle can get two sides of infrared-induced signs, and extracted based on infrared-induced line slope when vehicle can get one side of infrared-induced signs. The road trend is calculated by fitting the position of the infrared-induced signs in the road coordinate. Finally we have finished the basal research of the vehicle guidance in heavy fog.