Research on Expressway Distance Safety Warning Method for Heavy Fog Weather Based on Road Network Monitoring
The duration,intensity and scope of foggy weather are uncertain,resulting in dramatic changes in visibility on the expressway in a short period of time.It is difficult to accurately estimate and predict the maximum visible distance in foggy weather,which may cause inability to decelerate timely to avoid collision with the preceding vehicle.To solve this problem,a safety warning method based on road network monitoring is put forward.Transmittance of air is first calculated based on light intensity,and then the maximum visible distance under monitoring of road network is obtained.Further,the architecture of expressway vehicle distance safety warning system based on road network monitoring in foggy weather is constructed through segmentation of visibility image,introduction of dark channel weight,and removal of fog in the image using atmospheric refractive index map.Then braking distances of front and rear vehicles are calculated to obtain the critical safe driving distance.Experimental results show that the proposed method makes the rear vehicle decelerate faster than the front vehicle after early warning.Distance between vehicles keeps at 7 m to avoid collision when the braking time is 80 s.
road network monitoringheavy fog weathervisibilityexpresswaysvehicle distance safety warning
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