Output Feedback Prescribed Performance Control for Euler-Lagrange Systems with Application to a Robotic Manipulator

In this work, a novel output feedback control strategy for Euler-Lagrange systems that addresses the inherent uncertainties of nonlinear dynamics and feedback limitations is presented. The proposed method employs the Prescribed Performance Control (PPC) technique to ensure that the system's output tracks the desired reference trajectory within predefined performance specifications. Additionally, we introduce a novel tracking differentiator with adaptive gains to estimate the derivative of the tracking error, effectively overcoming practical challenges where the derivatives of the state and reference trajectory are unavailable. The effectiveness of the proposed scheme is validated through simulation results as well as a real-life experiment.