Robot non‐linearity bounds evaluation techniques for robust control

Abstract

Abstract Robust controller design approaches for non‐linear control systems usually require the evaluation of upper bounds on non‐linear quantities of the process for the robustness analysis. The conservatism and usefulness of robustness criteria are determined by the accuracy of the robustness bounds. This contribution deals with the robust control of robot manipulators and presents generally applicable evaluation techniques for bounds on robot manipulator non‐linearities which may be remnants of an incomplete non‐linear decoupling or feedback linearization. These bounds can be used to verify several robust stability criteria for the control of rigid and elastic joint robots. Apparently, these bounds give insight to the strength and significance of non‐linear couplings and may be used to judge whether complicated model‐based control laws should be preferred rather than simple linear controllers.