This paper investigates the fixed-time trajectory tracking control problem for a nonholonomic mobile robot. Firstly, the tracking error system is derived for the mobile robot by the aid of a global invertible transformation. Then, based on the unified error dynamics and by using the fixed-time control method, continuous fixed-time tracking controllers are developed for the mobile robot such that the robot can track the desired trajectory in a fixed time. Moreover, the settling time is independent of the system initial conditions and only determined by the controller parameters. Finally, numerical simulations are provided to demonstrate the effectiveness of the theoretical results.
In this paper, a novel approach for controlling complex networks is proposed; it applies sliding-mode pinning control for a complex network to achieve trajectory tracking. This control strategy does not require the network to have the same coupling strength on all edges; and for pinned nodes, the ones with the highest degree are selected. The illustrative example is composed of a network of 50 nodes; each node dynamics is a Chen chaotic attractor. Two cases are presented. For the first case the whole network tracks a reference for each one of the states; afterwards, the second case uses the backstepping technique to track a desired trajectory for only one state. Tracking performance and dynamical behavior of the controlled network are illustrated via simulations.