Distributed coordinated tracking control for multiple unknown nonlinear Euler-Lagrange systems

This paper studies a robust distributed consensus tracking problem for a class of multiple unknown nonlinear Euler-Lagrange systems where only a subset of the agents has access to the desired trajectory. A nonlinear identifier is first developed for each agent to estimate the unknown nonlinear dynamics and disturbances. Based on the identifier, a continuous distributed consensus tracking algorithm is developed to enable robust consensus tracking under an undirected graph. The closed-loop stability is proven by graph theory and Lyapunov analysis. By selecting the identifier and controller parameters according to the derived sufficient conditions, robust asymptotic consensus tracking can be enabled through local information exchange. An example is provided to illustrate the effectiveness of the proposed method.