Experimental Study on Tire-Road Dynamic Contact Pressure Distribution Using FTIR Imaging

The power source for accelerating, braking, and steering of the vehicle is derived from the contact force between tire and road. Therefore, the pressure distribution in the tire-road contact patch is imperative for explorative studies into tire and vehicle performance. A test bench for measuring tire-road dynamic contact pressure distribution was designed based on the frustration of total internal reflection (FTIR) imaging. The load, camber angle, slip angle, and rolling speed of the tire can be adjusted by the bench. The factors, including the color of calibration material and the ambient light, were studied to improve the calibration accuracy of the bench and solve the problem of recurring calibration of the bench at regular intervals. From the image captured by the camera, the contact region between the tire and the road was obtained by image processing technologies, including image correction, graying, filtering, and segmentation. The obtained contact region was converted into contact pressure distribution by the parameters obtained from calibration subsequently. Finally, the dynamic contact pressure distribution under different conditions, including different inflation pressure, load, camber and slip angles, was analyzed and the error is within a reasonable range.