ABSTRACT
The chapter presents a backstepping based distributed adaptive consensus tracking control scheme for a class of nonlinear systems with mismatched uncertainties. The subsystems are allowed to have non-identical dynamics, whereas with similar structures and the same yet arbitrary system order. The chapter summarises main differences between the presented scheme and the existing representative approaches: the communication status among subsystems is represented by a directed graph; and the nonlinearities accompanied with unknown parameters in each subsystem's dynamics cannot be assumed bounded in advance as those activation functions. To bypass this difficulty, an error variable is defined in each subsystem by introducing local estimates of the reference' uncertainties. Based on this, an alternative form of Lyapunov function is constructed. Moreover, the parameter update laws can be designed totally in a distributed manner without further information exchange of synchronization errors among subsystems. Apart from these, the proposed design strategy is successfully applied to solve a formation control problem for multiple nonholonomic mobile robots.
