Distributed fuzzy fault-tolerant consensus of leader-follower multi-agent systems with mismatched uncertainties

In this paper,the distributed fuzzy fault-tolerant tracking consensus problem of leader-follower multi-agent systems(MASs)is studied.The objective system includes actuator faults,mismatched parameter uncertainties,nonlinear functions,and exogenous disturbances under switching communication topologies.To solve this problem,a distributed fuzzy fault-tolerant controller is proposed for each follower by adaptive mechanisms to track the state of the leader.Furthermore,the fuzzy logic system is utilized to approximate the unknown nonlinear dynamics.An error estimator is introduced between the mismatched parameter matrix and the input matrix.Then,a selective adaptive law with relative state information is adopted and applied.When calculating the Lyapunov function’s derivative,the coupling terms related to consensus error and mismatched parameter uncertainties can be eliminated.Finally,a numerical simulation is given to validate the effectiveness of the proposed protocol.

Finite Control Set Model Predictive Control with Feedback Correction for Power Converters

As an open-loop model predictive control algorithm,finite control set model predictive control(FCS-MPC)scheme in power converter system is based on assumption that responses of optimal control implemented on prediction model agree well with actual system.The influence of model parameter mismatches and environment disturbance on control performance of scheme is neglected.Then,based on feedback correction strategy in traditional model predictive control algorithm,we derive a finite control set model predictive control with feedback correction scheme(FCS-MPCFC)that allows us to adjust prediction model output at current instant by model prediction error at previous instant,and the closed-loop correction of prediction model output is achieved.Simulations comparison analyses on a two-level three-phase inverter with multi-type model parameter mismatches controlled by traditional and improved FCS-MPC scheme are presented.Experiments are carried out on DSP controller platform.

Cooperative behaviors of coupled nonidentical oscillators with the same equilibrium points

The cooperative behaviors resulted from the interaction of coupled identical oscillators have been investigated intensively.However,the coupled oscillators in practice are nonidentical,and there exist mismatched parameters.It has been proved that under certain conditions,complete synchronization can take place in coupled nonidentical oscillators with the same equilibrium points,yet other cooperative behaviors are not addressed.In this paper,we further consider two coupled nonidentical oscillators with the same equilibrium points,where one oscillator is convergent while the other is chaotic,and explore their cooperative behaviors.We find that the coupling mode and the coupling strength can bring the coupled oscillators to different cooperation behaviors in unidirectional or undirected couplings.In the case of directed coupling,death islands appear in two-parameter spaces.The mechanism inducing these transitions is presented.