Delta机器人综合位置误差研究及其耦合特性分析

以Delta机器人为分析对象,研究了动平台的位置误差模型,并对误差源的耦合特性进行了分析。首先,利用从动臂的位置特性,依据几何空间矢量法,建立了Delta机器人机构误差模型;其次,以数理统计与空间矢量原理为基础,推导出Delta机器人关节间隙误差模型;然后,基于空间有限元理论,在建立系统弹性动力学模型的基础上建立了其柔性误差模型;综合考虑这3种误差源,建立了Delta机器人综合位置误差模型;最后,利用Adams与Workbench联合仿真、Matlab数值计算和FARO激光跟踪仪的现场试验验证了位置误差模型的正确性,并对误差源的耦合特性进行了分析,阐述了方向位置误差与坐标轴方位之间的关系。结果表明,影响Delta机器人动平台位置误差的各个误差源间并不是简单的叠加,而是具有明显的耦合特性,并且动平台方向位置误差会随着坐标轴方位的变化而变化。

Comprehensive Position Error of Delta Robot and Analysis of Its Coupling Characteristics

Taking Delta robot as the object of analysis, studying the position error model of the moving platform, and the coupling characteristic of the error source is analyzed. Using the position characteristic of driven arms, based on the method of geometry space vector, the mechanism error model of Delta robot is established; Using the principle of mathematical statistics and space vector as the basic, the joint clearance error model of Delta robot is derived; Based on finite element theory, on the basic of elastic dynamic model of Delta robot, the flexible error model is eatablished; Then, considering the three kinds of error source, the comprehensive position error model of Delta robot is established. Finally, by use of simulation software of Adams and Workbench, numerical calculation of Matlab and field experiment of FARO laser tracker, the correctness of comprehensive position error model is verified, and coupling characteristics of the error sources are analyzed, the relationship between position error and the axis''s azimuth of system coordinate is elaborated. The results show that the error sources that affect the position error of the Delta robot''s moving platform are not simply superimposed, but with obvious coupling properties, and the directional position error of the moving platform changes with the azimuth of the coordinate axis.