基于横向不平度的越野路面模型分形构造

Fractal Modeling of off-road Terrain Based on the Transverse Unevenness

为了在虚拟环境中获得具有真实感的越野路面模型,提出该模型分形构造方法.首先选取砾石路面作为典型的越野路面,对纵向和横向高程数据样本进行采集和数据预处理.然后运用纵、横向高程数据构造得到路面样片,并运用分形B rown ian运动计算其自相关函数.利用Hurst系数估算路面模型的分形维数,并基于层最小能量准则获得路面最佳高程.通过改变最佳高程参数和分形维数控制路面的三维形状和表面粗糙度.结果表明,构造得到的路面模型具有自相似性、真实感强的特点,并且每个取样的功率谱密度、载荷输入等均为已知,符合仿真测试的要求.

In order to obtain immersional off-road terrain model in virtual environment, the fractal construction algorithm is put forward. First, the longitudinal and transverse height of the gravel terrain are sampled and preprocessed as a typical off-road terrain. Then the terrain slice is constructed according these data along two directions, and the autocorrelation function is calculated according to the fractal Brownian motion method. The fractal dimension is evaluated by Hurst coefficient, and the terrain optional height is calculated according to the layer minimum energy rule. The spatial model and the surface rough- ness are adjusted by change the optional height and the fractal dimension. The results show that the terrain modeling is self similar and impersonal. The power spectrum density and the load input are calculated at each sampling site, and meet with the simulation requirements.