基于动力学性能的全柔性机构优化设计

OPTIMAL DESIGN OF A FULLY COMPLIANT MECHANISM BASED ON ITS DYNAMIC CHARACTERISTICS

全柔性机构是一种新型机构,多应用在精密定位场合。为保证该机构具有很高的定位精度和较强的抗环境干扰能力,仅以静力学性能作为指标进行机构的优化设计是不足以满足要求的,还需要对机构的动力学性能进行优化。研究以一具体的全柔性机构为例,给出一种基于机构动力学性能的结构优化设计方法。为此首先建立了该机构的动力学理论模型,为保证结果的准确性,还进行了有限元模拟;在设计过程中,同时考虑到了机构的静态特性与动态特性。该方法可有效地完成机构的尺度综合。

The fully compliant mechanism is a new type of mechanism which is often used as a micro-positioning stage. However, it is very hard to make sure that the mechanism has a high positioning accuracy and a good ability of resisting the external disturbance, if the static characteristics of the mechanism as the single design objective are considered during the its structural optimization while ignoring its dynamic characteristics such as natural frequency. Thus an optimal design method of the fully compliant mechanism based on its dynamic characteristics is presented by taking a concrete fully compliant mechanism i.e. the parallel guided compliant mechanism for example. In order to realize it, the dynamic model that characterizes this mechanism is proposed to predict the first order natural frequency, and the finite element simulation is also adopted to revise the theoretic result. In addition, although the optimization for the mechanism is based on its dynamic characteristics, its static ones are also in discussion.