Design Of Gain-Scheduling PID Controller For LPV Systems

In practice,a plenty of plants and processes are highly nonlinear.Generally speaking,it does not satisfy the performance if we only use the traditional linear method to control the practical systems.Taking the nonlinear control methods will make it more complex to realize in engineering.There are a lot of nonlinear systems,such as air vehicle,aero engine and so on,which can be modeled as linear parameter varying(LPV)systems.Then,by means of the theory of linear systems,the stability,robustness,tracking performance of systems can be guaranteed,which make it convenient to analyze the practical systems and design the controller.As for the controller design,with its simplicity and effectiveness,PID controller is widely used in industry control.On the other hand,with the development of computer network technology,event-triggered mechanism is proposed to save the communication source with respect to the traditional time-triggered control.In addition,we can design the event-triggered mechanism to guarantee the system performance.In this thesis,we consider the LPV systems to study the regional regulation,H? tracking control and constant output tracking control,which refer to the design of gain-scheduling PID controller,event generator and state observer.The main contents of this thesis are as follows:Firstly,we consider the first-order unstable LPV plant and combine the regional poles of the closed-loop system with the system output time-domain dynamic performance specifications to obtain the gain of gain-scheduling PID controller,gain-scheduling PI controller and incomplete differential gain-scheduling PD respectively,which assign the poles of the closed-loop system in the specified complex plane region and make the system satisfy the specific dynamic performance.The simulation results verify the feasibility and effectiveness of the theoretical results.Then,we consider the LPV systems and design the switched gain-scheduling controller based on event-triggered mechanism to achieve the H? tracking control of Linear Time Invariant(LTI)reference system.By means of the switching rule for average dwell time,we divide the parameter region into small sub-regions and make the sufficient condition to guarantee H? tracking performance under the co-design of the switched gain-scheduling controller and event generator.The optimal weighted H? performance obtained with the switched gain-scheduling controller is less than the optimal weighted H? performance obtained with single gain-scheduling controller,which means that the switched method promotes the system's ability to suppress external disturbances.Besides,we also give the proof that the lower bound of time interval in which two consecutive triggers occur is strictly positive,which avoids the Zeno phenomenon and has theoretical and practical significance.The simulation results verify the feasibility and effectiveness of the theoretical results.Finally,we consider the LPV systems with incompletely measurable state and provide the sufficient condition to jointly design the gain-scheduling PI controller based on event-triggered mechanism and two event generators that update the system state and parameters to achieve the tracking of constant reference signal.Moreover,we give the proof that the accurate tracking of constant output signal can not be achieved with the gain-scheduling P controller.Besides,we give the proof that the lower bound of time interval in which two consecutive triggers occur is strictly positive,and obtain that the lower bound is related to the event-triggered condition threshold and the upper bound of the change rate of the parameters.The simulation results verify the feasibility and effectiveness of the theoretical results.