Research On The Anti-Windup Control Of Aerostat With Input Constraits

In this paper,the multi-vectored thrust aerostat is taken as the research object.Considering the limited input amplitude and rate of the system,the anti-windup controller is designed by using the nested saturation function.The main work of the dissertation is as follows:Firstly,a three-degree-of-freedom nonlinear model in the plane of a multi-propeller vector thrust aerostat is established,and linear programming is used to distribute the vector thrust of propellers.Second,the theory of nested saturation controller design is introduced,and two cases of amplitude and rate constrains are described by the traditional nested saturation controller.For the single-channel nonlinear model of aerostats,a third-order nested saturation controller is designed.The effectiveness of the control law is verified by simulation.Then the traditional nested saturation control is studied,the steady state error is eliminated by compensating the disturbance,thus the control law is improved and better dynamic performance is achieved.Furthermore,estimation of the attraction domain of the aerostat subjected to model uncertainty and external disturbance is performed to verify the local stability of the closed-loop system.Finally,a second-order nested saturation control law is designed for the aerostat in combination with the differential bounded theory of nested saturation function.Propeller amplitude and rate saturation constraints are guaranteed and the proof of the closed-loop stability is given.The relationship between controller parameters and the dynamic performance of the system is studied.The research results show the effectiveness of the nested saturation control law on the input constraint system.The traditional nested saturation controller that is a passive anti-saturation control method can realize the control of the actuator amplitude and rate constraints.The local stability is obtained by estimating the attraction domain.The nested saturated differential bounded method can be used to describe the amplitude and rate constraints of the system.The relationship between the saturation function parameters and the rate constraint can be obtained analytically to solve the controller parameters.Due to the continuous differentiability of the saturation function,the flexibility of the controller design is increased.