Reliable Control for Nonlinear Systems with Stochastic Actuators Fault and Random Delays Through a T-S Fuzzy Model Approach

This paper considers the reliable control design for T-S fuzzy systems with probabilistic actuators faults and random time-varying delays.The faults of each actuator occurs randomly and its failure rates are governed by a set of unrelated random variables satisfying certain probabilistic distribution.In terms of the probabilistic failures of each actuator and time-varying random delays,new fault model is proposed.Based on the new fuzzy model,reliable controller is designed and sufficient conditions for the exponentially mean square stability(EMSS) of T-S fuzzy systems are derived by using Lyapunov functional method and linear matrix inequality(LMI) technique.It should be noted that the obtained criteria depend on not only the size of the delay,but also the probability distribution of it.Finally,a numerical example is given to show the effectiveness of the proposed method.

Reliable control of discrete-time linear systems with actuator failure

A sufficient condition is given for robust stability of a discrete linear system in which an arbitrary portion of input channel is permanently attenuated or disconnected due to actuator fault.The partial disconnection/attenuation of the control input,is modelled as uncertainty and dealt with via a robust control method.The proposed method enables one to design a controller in such a way that the closed loop system remains stable when any combination of input signals is disconnected if the open loop system is stable and fulfils some additional properties.It is shown that the linear quadratic regulator can guarantee reliable closed loop with some specific choices for weighting matrices.The result is extended to unstable systems by assuming additional constraints on the failed actuators.Compared to previously established results,the proposed conditions are easier to verify and applicable to a wider class of systems.An example is also included.

Non-fragile reliable control for positive Markovian jump systems based on event-triggered mechanism

This paper is concerned with the non-fragile reliable control of positive Markovian jump systems with actuator saturation based on event-triggered mechanism.First,an event-triggering condition is given in the form of 1-norm.Using a stochastic co-positive Lyapunov function,a design approach is proposed for the non-fragile controller gain and the corresponding auxiliary feedback gain.Under the designed controller,the closed-loop system is positive and stochastically stable even if actuator faults occur.A cone is constructed as the invariant set of the systems.All conditions are solvable in terms of linear programming.Finally,two examples are provided to verify the effectiveness of the obtained results.

Model-Based Fault Tolerant Control for Hybrid Dynamic Systems with Sensor Faults

A model-based fault tolerant control approach for hybrid linear dynamic systems is proposed in this paper. The proposed method, taking advantage of reliable control, can maintain the performance of the faulty system during the time delay of fault detection and diagnosis (FDD) and fault accommodation (FA), which can be regarded as the first line of defence against sensor faults. Simulation results of a three-tank system with sensor fault are given to show the efficiency of the method.