Screw theory based error modeling method of robot mechanisms

Abstract

Based upon the exponential matrix and exponential products of modern screw theory for the description of rigid body transformation,the pose error of kinematic pair axis is treated as the result of equivalent screw motion,and an error model of robot is built by using the products of exponentials formula.Meanwhile,the position and orientation errors of tool tip are represented as prismatic and revolute pair's screw motions respectivly,and the calculation formulas are presented.Using SCARA robot as an example,the simulation experiment is done with Matlab and Adams,and the results show that the presented modeling method is intuitive and correct.