Fuzzy Sampled-data Directional Control For Autonomous Airships

The autonomous airship is investigated and the heading motion control of the airship is mainly studied in this paper.The heading motion of airship has the characteristics of high non-linearity and strong coupling.At the same time,the control systems are implemented as digital systems and discrete control systems.Therefore,this paper combines the fuzzy control and sampling control methods to study the heading control of the airship.As a kind of fuzzy model,T-S fuzzy model has been extensively studied in the pastyears and it provides an efficient strategy to analyze and synthesize a highlynonlinear dynamic system.On the other hand,with the development of digital technique,the adoption of discrete-time-signal-based sampled-data controller becomes popular.This paper aims to study directional sampled-data control of a class of T-S fuzzy-model-based autonomous airship.For fuzzy directional control system of an autonomous airship,a kin d of fuzzy time-dependent Lyapunov functional is adopted to study the sampled-data control problem.Compared with some of existing functionals,this functional can fully utilize the characteristics of fuzzy systems.Based on the functional and linear matrix inequality technique,the asymptotic stability of closed-loop system is analyzed,and the conditions for the existence of the controller are presented.The effectiveness of the developed methodology is verified by simulations.To reduce the transmission burden of the control signal can improve the reliability of the control system,and the size of transmission has a close relationship with the size of sampling interval.The fuzzy sampled-data controller with time-varying gains is used to study the directional control problem of the autonomous airship.Based on the Lyapunov functional and linear matrix inequality technique,the asymptotic stability of closed-loop system is analyzed,and the conditions for the existence of the controller are presented.Simulation results show that the new controller can effectively achieve directional tracking of the autonomous airship under a larger sampling interval thanthe one using fuzzy sampled-data controller with constant gains.Event-triggered mechanism is another efficient way to reduce the transmission burden.We further design an adaptive event-triggered mechanism and a fuzzy sampled-data controller.By combing time-dependent Lyapunov functional with linear matrix inequality technique,a solution for the designed controller is provided.Simulation results show that the designed controller can effectively achieve directional tracking whilst less transmission burden is needed.Actuator failures often happen during the operation of the airship.The stochastic actuator failures are considered and a reliable fuzzy sampled-data controller is designed.By combing time-dependent Lyapunov functional with linear matrix inequality technique,a solution for the designed controller is provided.Simulation results show that the designed controller can effectively achieve directional tracking despite the stochastic actuator failures.