Decentralized Control of Multiple Strict-Feedback Systems With Unknown Control Directions

This paper is concerned with the decentralized control problem of networked high-order nonlinear systems that can be transformed into strict feedback forms with parameter uncertainties and unknown control directions under a directed communication graph. A decentralized controller is designed recursively for each agent to realize output synchronization and guarantee the overall system to be bounded. Instead of a Lyapunov-based argument which is commonly used in the literature, an inductive contradiction argument is employed. Moreover, not like other existing works, we use the Nussbaum function in the analysis function form rather than its derivative, which not only facilitates the proof but also enlarges the schedule's application scope. Simulation results are presented to verify the effectiveness of the proposed scheme.