In view of the waving motion of trees, a simulation on the broken branches caused by big wind was proposed. After analyzing the motion details using dynamics, the formula of deformation of trees, which was used to interpret character statistics, was obtained. By using Perlin noise function to simulate dynatic wind fields, the simulation of broken branches was realized with different expressions. The experiment result shows that trees move as a whole body conforming to the continuity and consistency of physics until being randomly broken down under wind fields. The method is valid and can be applied in virtual reality to simulate broken branches caused by big wind.

Concerning the parameter optimization of electric assist control strategy for Hybrid Electrical Vehicles (HEV), the orthogonal table was designed based on the theory of orthoplan experiment, which took the fuel consumption, the COs emission, and the total emission of HC and NOx as the experimental indexes. The influence of control strategy parameters on the parallel HEV was obtained by using intuitive analysis to analyze the 18 group test results, and then the remarkably influencing factors of each index were found out.