Study Of Road Roughness Based On Farctal Theory

Road roughness produces the resistance and vibration when a vehicle is being driven. Resistance consume the power of vehicle and affect life-span of dynamic system or transmission system. The vibration affects comfort and calm capability, as well as the life-span and reliability of load system. People start realized the importance of road roughness with get deep into investigation.In this article, the real data of road roughness is analyzed by traditional way. The result shows that more parameters are required when describe the whole characteristic of the road. That is say, the traditional parameter is not the only with the road, it will change with the resolving power of measure equipment. So it is essential to find a new parameter.Fractal theory is developed in recent years. It is widely used in signal description and disposal. It is a important embranchment in scientific study. Legion studies show that fractal theory can describe the essence trait of complex phenomenon. The real road roughness is analyzed by fractal theory in this article.The means of different computation are compared, the result turn up that root square and variance method are more precision. Considerate the object, the road data is analyzed by root square method in this task. Result discovery that the concrete fractal dimension is the tiptop, the brick is about one point seven and the soil is about one point six. The contour curve becomes complex with the increasing of fractal dimension. At the same time, the root square of profile is decreasing when the fractal dimension is increasing. The roughness index can reflect the characteristic of surface uniquely.Weierstrass-Mandelbrot function is fine model when depict the roughness surface. Engineering peculiarity and physics meaning of Weierstrass-Mandelbrot function is studied in the article. After simulating the real road by W-M function find that this model can reflect the genius trait of simulacrum.In the end, the three fractal dimension of road picture is computed by image manipulation technology, the result show that there is obvious distinction among different road. By the method, we can classify the different road exactly, this settle the foundation on three dimension study of road roughness.