中文摘要：

通过自动调节多刚体系统中每个构件上自然坐标系的形态，达到自动选择自然坐标的目的。提出了自然坐标系的自适应调节方法：首先，为标准自然坐标系找出周边所有基点空位和矢量空位并对其加权；然后，剔除冗余空位并调整权值；接着，找出最多4个权值总和最高的可行空位；最后，标准自然坐标系调节自身形态以占据所有可行空位。调节结果是实际的自然坐标系，它为该构件提供12个合理的自然坐标。在多体动力学仿真平台InteDyna上实现了该方法，提高了自然坐标法的建模效率和建模质量。

英文摘要：

A self--adaptation method for natural--coordinate systems was proposed, in order to select natural coordinates automatically for each rigid elements of a multibody system. A four--step method includes.first, find out all empty positions, which come from the feature points or vectors of the joints attached to an element, and give equal weight to them; second, delete redundant empty po sitions and add their weight to the unique one; third, select at most four empty positions which have a maximum total weight and can be occupied by a natural--coordinate system at the same time~ fourth, the standard natural--coordinate system on the element can adapt itself to the selected empty positions,leading to an actual natural--coordinate system, which contains twelve rational natural coordinates for the element. The implementation of the method was achieved on a multibody dynamics and motion analysis platform, InteDyna, resulting in modelling efficiency enhanced and model quality improved.