Robot positioning error analysis and correction

Abstract

The applicability and productivity of industrial robots have been limited partly because of positioning errors. In this thesis, two causes of positioning errors are identified: link deflection and gear transmission errors. Positioning errors due to the effect of link deflection and gear transmission errors are discussed and an iterative scheme is introduced to compute the deflected end-effector position. Validity of the scheme is verified by using Castigliano’s method on the same two-link hypothetical robot. Numerical integration of the integral equations of deflections is compared with analytical integration A correction method is then proposed and an error corrector is constructed. Effectiveness of the error corrector is demonstrated with a hypothetical RRRS robot, a 3-link robot with revolute joints and a spherical hand.