This article studies the adaptive fault tolerant control (AFTC) and collision avoidance problem for wheel mobile robots (WMRs) under event-triggered mechanism and communication constraints. The dynamics of WMRs and their transformation are considered first. To handle the constraint that only part of the robots can access the leader, the distributed state estimators are designed. Simultaneously the actuator faults and external disturbances are approximated by cerebellar model neural network. Then, an event-triggered-based AFTC and collision avoidance scheme is developed by utilizing a backstepping control technique and artificial potential field. The stability of the closed-loop system is proved and Zeno behaviors are excluded. Finally, the simulation evaluation and experimentation of three robots is implemented to illustrate the superiority of the presented scheme.
6 December 2013 in Transactions of the Institute of Measurement and Control
This paper deals with the problem of state feedback stabilization with finite-time stochastic stability for a class of discrete-time switched stochastic linear systems under asynchronous switching. The attention is focused on designing the feedback controller that guarantees the finite-time stochastic stability of the dynamic system. The finite-time stochastic stability definition of discrete-time switched stochastic systems is introduced. The asynchronous switching idea originates from the fact that switching instants of the controllers lag behind or exceed those of subsystems. On the basis of the average dwell time method and multiple Lyapunov functions approach, a finite-time stochastic stability condition is established. Then, an asynchronously switched controller is designed and the corresponding switching law is derived to guarantee the considered system be finite-time stochastically stable. Two numerical examples are provided to show the effectiveness of the developed results.
16 June 2021 in International Journal of Adaptive Control and Signal Processing
This paper studies the problem of stabilising a sampled-data switched linear system by quantised feedback asynchronously switched controllers. The idea of a quantised feedback asynchronously switched control strategy originates in earlier work reflecting actual system characteristic of switching and quantising, respectively. A quantised scheme is designed depending on switching time using dynamic quantiser. When sampling time, system switching time and controller switching time are all not uniform, the proposed switching controllers guarantee the system to be finite-time stable by a piecewise Lyapunov function and the average dwell-time method. Simulation examples are provided to show the effectiveness of the developed results.
1 December 2019 in Transactions of the Institute of Measurement and Control
Finite-time stability and stabilization for switched nonlinear systems has been investigated in the paper. Based on existing works, we find that related results on autonomous switched nonlinear systems cannot be simply extended to non-autonomous systems. A sufficient condition has been proposed for this class of systems using the average dwell time method. Specifically, a control Lyapunov function approach is employed to stabilize the system and the finite-time controller is designed using a small control property. In contrast to autonomous switched systems, a finite-time stabilizer is constructed for time-varying switched nonlinear systems, even under the situation in which the switching mode is different between the system and the controller. Furthermore, the relation between the settling time and the average dwell time has been revealed. Finally, an example case is presented for the obtained result.