双簧片导向机构的传递误差分析

双簧片导向机构是接触式测量常用的核心部件,广泛应用于自动检测中,其传递误差的模型直接影响传感器的测量精度.传统的建模方法采用悬臂梁整体柔性建模,不符合实际物理结构,在测量中会引起较大的传递误差.在建立导向机构整体力学模型的基础上,提出簧片机构柔-刚-柔悬臂梁分段建模方法,推导出簧片作用力和弯矩表达式,继而得出平动板寄生转角和传递误差表达式.最后通过有限元计算仿真技术,对悬臂梁分段模型与悬臂梁整体柔性模型进行仿真分析.仿真结果表明,柔-刚-柔悬臂梁分段建模方法比传统悬臂梁整体柔性建模方法的传递误差明显减小,验证了模型的有效性,从而为双簧片导向机构的设计、测量精度的动态补偿以及测量后数据处理提供了理论依据.

Transfer Error Analysis of Double-Reed Guide Mechanism

As the core component of contact measurement mechanism,double-reed guide mechanism is widely used in automatic detection,and its transfer error modeling directly affects the measurement accuracy of the sensor. The overall flexibility modeling of cantilever beam is adopted in traditional modeling methods,which however,does not accord with the actual physical structure and can lead to greater transfer error in the measurement. In this paper,the overall mechanics model of the guide mechanism was established firstly,and then the cantilever beam segment modeling methods of flexibility-rigid-flexibility of reed mechanism was proposed. Based on this method,the reed force and the bending moment expressions were deduced,so that the parasitic rotational angle of translational board and the transfer error expressions were obtained. Finally,through the finite element simulation technology,the simulation experiments were conducted and the simulation results suggest that the transfer error of the cantilever beam segment modeling method of flexibility-rigid-flexibility was greatly reduced,compared with the overall flexibility modeling method of cantilever beam. Therefore,the model proposed in this paper is proved to be effective,and it also provides theoretical basis for design of double-reed guide mechanism,dynamic compensation of measurement accuracy and data processing.