Boundary Output Feedback Control for a Flexible Two-Link Manipulator System With High-Gain Observers

This brief focuses on the boundary output feedback control for a flexible two-link manipulator (FTLM) system with input saturation. For the purpose of suppressing elastic vibration and regulating manipulator's angular position, boundary output feedback controllers (BOFCs) are proposed. When the system states cannot be directly measured, a set of high-gain observers are designed to reproduce these immeasurable system states. Simultaneously, in order to solve the problem of excessive control input caused by high-gain observers, two auxiliary systems are designed to compensate for the input saturation. The stability of the FTLM system is obtained through mathematical analysis. Furthermore, the effectiveness of the designed controllers is proved by numerical simulations.