Optimum calibration of a parallel kinematic manipulator using digital indicators

作     者：V.B.Saputra S.K.Ong A.Y.C.Nee 

作者机构：Department of Mechanical EngineeringFaculty of EngineeringNational University of SingaporeSingapore 117576Singapore 

出 版 物：《Advances in Manufacturing》 (先进制造进展（英文版）)

年 卷 期：2014年第2卷第3期

页      面：222-230页

核心收录：

学科分类：080202[工学-机械电子工程] 08[工学] 0804[工学-仪器科学与技术] 0802[工学-机械工程] 

主　　题：Calibration Parallel kinematic manipulator(PKM) Digital indicator 

摘      要：This paper presents a calibration method for parallel manipulators using a measurement system specially installed on an external fixed frame. The external fixed frame is important as an error reference for calibration in certain operations, such as in the configuration of a parallel manip- ulator functioning as a machine tool where the workpiece is fixed to a worktable. The pose of the end-effector is mea- sured using three digital indicators installed on the external fixed frame. To enable measurement, the end-effector is assumed to be a plane large enough that all digital indicators could touch. The error is defined as the difference between the theoretical and actual readings of the digital indicators. The geometric parameters of the parallel manipulator are optimized to minimize this error. This calibration method is low cost and feasible for compensating geometric parameter errors for a parallel manipulator. Optimal pose selection for the calibration is achieved using a swarm intelligence search algorithm. The method is implemented on a prototype of a six degrees-of-freedom （DOFs） Gough-Stewart platform constructed to function as a machine tool.