Robustness analysis of nonlinear decoupling for elastic-joint robots

A robustness analysis of feedback linearization or nonlinear decoupling is proposed for a class of elastic-joint robot manipulator control loops. It is shown that by splitting the modeling-error nonlinearities of incomplete feedback linearization or nonlinear decoupling by a suitable transformation, a robustness analysis becomes feasible under weak assumptions without the necessity of estimating bounds on derivatives of robot nonlinearities. In principle, systems other than elastic-joint robots can be investigated using the proposed methodology, which makes any robustness analysis and synthesis of feedback linearization or nonlinear decoupling more transparent