Gravity-Based Kinetostatic Modeling of Parallel Manipulators Using Screw Theory  

作　　者：Chao Yang Fengli Huang Wei Ye Qiaohong Chen 

机构地区：[1]College of Mechanical and Electrical Engineering,Jiaxing University,Jiaxing 314001,China [2]National and Local Joint Engineering Research Center of Reliability Analysis and Testing for Mechanical and Electrical Products,Zhejiang Sci-Tech University,Hangzhou 310018,China [3]School of Computer Science and Technology,Zhejiang Sci-Tech University,Hangzhou 310018,China

出　　处：《Chinese Journal of Mechanical Engineering》2023年第6期73-86,共14页中国机械工程学报（英文版）

基　　金：Supported by National Natural Science Foundation of China(Grant No.52275036);Key Research and Development Project of Jiaxing Science and Technology Bureau of China(Grant No.2022BZ10004).

摘　　要：The pose accuracy of parallel manipulators(PMs)is a key index to measure their performance.Establishing the grav-ity-based kinetostatic model of a parallel robot provides an important basis for its error composition and accuracy improvement.In this paper,a kinetostatic modeling approach that takes real gravity distribution into consideration is proposed to analyze the influence of gravity on the infinitesimal twist and actuator forces of PMs.First,the duality of the twist screw and constraint wrenches are used to derive the gravity-attached constraint wrenches independent of the external load and the limb stiffness matrix corresponding to the kinematics-based constraint wrenches.Sec-ond,the gravity model of the mechanism is established based on the screw theory and the principle of virtual work.Finally,the analytical formulas of the infinitesimal twist and the actuator force of PMs are obtained,and the influences of the external load,platform gravity,and rod gravity on the stiffness of the mechanism are decoupled.The non-overconstrained 3RPS and overconstrained 2PRU-UPR PMs are taken as examples to verify the proposed method.This research proposes a methodology to analyze the infinitesimal deformation of the mechanism under the influence of gravity.

关 键 词：Parallel manipulator Kinetostatic model GRAVITY Screw theory 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置] TH112[自动化与计算机技术—控制科学与工程]