大型铰接并联六维测力平台摩擦建模

在已有制造工艺及标定技术基础上,为进一步改善大型铰接并联六维测力平台的测量精度,本文基于螺旋理论和影响系数原理,引入符号函数建立了Stewart结构大型铰接六维测力平台的摩擦模型。文中提出了关节摩擦对铰接并联六维测力平台测量精度的影响矩阵及I、H类误差表达式,绘制了在不同外载和关节摩擦系数条件下,六维测力平台的I、II类误差曲线,并总结丁关节摩擦和平台自重对测力平台测量精度的影响规律。为具有普通球形铰链人型Stewart平台六维测力下台精度的提高和改善提供了理论基础。

To further improve the precision of sizable parallel 6-axis force platform With gemels the basis of present manufacture and calibration techniques,the paper adopts the sign function,and presents the friction model of platform with Stewart structure based on the screw theory and theory of influence coefficient.The influence matrix and expressions of type I and type II errors are also stuclied,which indicate the effect of joint-friction upon precision of measuremeut.Then,the graphs of type and type II errors of the parallel lbrce plate in the condition of different external forces and friction coefficient are plotted and the law how the joint-friction and the gravity of upper platform affect the precision of measurement is analyzed.Thus,the powerful basis and method are raised for the improvement and amelioration of the precision of sucha force measuring platform with general spherical joint.

国家自然科学基金(50375134,50675191);;中国科学院沈阳自动化所机器人学开放实验室资助项目