Error Modeling and Sensitivity Analysis of a Parallel Robot with SCARA(Selective Compliance Assembly Robot Arm) Motions

作     者：CHEN Yuzhen XIE Fugui LIU Xinjun ZHOU Yanhua 

作者机构：Department of Mechanical Engineering Tsinghua University Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and ControlTsinghua University Institute of Aircraft Engineering Naval Aeronautical and Astronautical University 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2014年第27卷第4期

页      面：693-702页

核心收录：

学科分类：081803[工学-地质工程] 080202[工学-机械电子工程] 08[工学] 0818[工学-地质资源与地质工程] 0804[工学-仪器科学与技术] 0802[工学-机械工程] 

基　　金：Supported by National Natural Science Foundation of China(Grant No.51305222) National Key Scientific and Technological Program of China(Grant No.2013ZX04001-021) 

主　　题：parallel robot selective compliance assembly robot arm(SCARA) motions error modeling sensitivity analysis parallelogram structure 

摘      要：Parallel robots with SCARA（selective compliance assembly robot arm） motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parallelogram structures included by the robots as a link. As the established error model fails to reflect the error feature of the parallelogram structures, the effect of accuracy design and kinematic calibration based on the error model come to be undermined. An error modeling methodology is proposed to establish an error model of parallel robots with parallelogram structures. The error model can embody the geometric errors of all joints, including the joints of parallelogram structures. Thus it can contain more exhaustively the factors that reduce the accuracy of the robot. Based on the error model and some sensitivity indices defined in the sense of statistics, sensitivity analysis is carried out. Accordingly, some atlases are depicted to express each geometric error’s influence on the moving platform’s pose errors. From these atlases, the geometric errors that have greater impact on the accuracy of the moving platform are identified, and some sensitive areas where the pose errors of the moving platform are extremely sensitive to the geometric errors are also figured out. By taking into account the error factors which are generally neglected in all existing modeling methods, the proposed modeling method can thoroughly disclose the process of error transmission and enhance the efficacy of accuracy design and calibration.