Finite-time Consensus of Networked Euler-Lagrange Systems via STA-based Output Feedback

The consensus problem based on full state feedback has been extensively studied, but rarely for leaderless distributed finite-time consensus of networked Euler-Lagrange systems based on output-feedback. In this work, the finite-time consensus problem of networked Euler-Lagrange systems subject to unknown velocity is studied. A finite-time consensus protocol is first proposed based on the relative positions and velocities. Then, the more challenging situation of networked Euler-Lagrange systems subject to unmeasurable velocity is considered. A model-independent observer based on the super-twisting algorithm (STA) is developed for velocity error estimation, based upon which a finite-time output feedback control protocol is developed for consensus of the networked Euler-Lagrange systems. Stability analysis shows that the networked Euler-Lagrange systems can achieve consensus in finite time. Finally, numerical simulations are conducted to demonstrate the effectiveness of the proposed control algorithms.