以刚度为目标的微位移放大模块闭环设计方法

目前全柔性机构的设计一般需要根据经验先估算机构的结构尺寸,再对机构的刚度进行研究。如果刚度不能满足要求,需要再次根据经验调整机构的结构参数。这种设计方法缺乏系统的理论依据,因此以刚度为目标的机构设计存在很大的盲目性且难以实际应用。以一种微位移放大模块为研究对象,提出一种基于刚度目标的闭环设计方法。通过伪刚体模型法建立微位移放大模块的简化刚度模型,根据柔性机构中各个柔性单元之间的几何关系和应变能分布关系确定各柔性单元的刚度性能,并进一步确定微位移放大模块的各结构尺寸。同时开发微位移放大模块刚度的参数化有限元分析程序,基于软件分析结果和机构参数与刚度的关系模型,可以根据精度要求对机构参数进行修正,实现了以刚度为目标的机构参数的闭环设计。

Closed Loop Design Method of Micro-driving Displacement Amplifier Module Targeting for Stiffness

For fully compliant mechanism,the general design method is to estimate all the structure parameters experientially in advance and then analyze its accurate stiffness.It is unavoidable to make amendments on certain parameters in condition that the computed stiffness doesn’t meet the given requirements.And unfortunately,this process depends greatly on one’s experience.Being devoid of systematic theory foundation,the parameter design method is blindfold and difficult to be put into practice.Taking micro-driving displacement amplifier module as example,a closed loop method is presented for design of structure parameters targeting for stiffness.Simplified stiffness model of the micro-driving displacement amplifier module is established through pseudo-rigid-body model method.Every compliant cell’s stiffness can be decided by their geometry relationship and strain energy distributions.And then the parameters of the micro-driving displacement amplifier module will be determined.The FEM program is also developed for parameters design and analysis of this module.For any given precision requirement,the structure parameters can be easily modified based on the software analysis result and the stiffness-parameter relationship model.And then how to obtain the accurate structure parameters targeting for stiffness has realized a kind of closed loop design.