Predefined-time leader-following consensus for nonholonomic chained-form multiagent dynamic systems

In addition to stability and accuracy, rapidity is another important index of the performance of control systems. The current fixed time design cannot meet the requirement for rapidity. The design to meet this requirement must be such that the settling time can be given in advance, that is, the so-called predefined-time design. This paper deals with the predefined-time consensus problem for a class of nonholonomic chained-form multiagent dynamic systems with unknown disturbances. First, a distributed observer for each follower is investigated such that the leader state can be estimated by the followers in a predefined time. Based on this observer, a switching consensus tracking controller is proposed to ensure that the tracking errors converge to zero within a predefined time. Compared with the existing finite-time and fixed-time schemes, the upper bound of the settling time is an directly tunable control parameter, and the settling time can be easily tuned by the control parameter. The stability of the closed-loop system is proved by the Lyapunov method. A simulation example of wheeled mobile robots is performed to demonstrate the effectiveness of the proposed controllers.