Research And Application Of Robust Control Based On Adaptive Dynamic Programming

With the improvement of industrial production level,the requirement for control precision of related industrial processes is gradually increasing.However,various uncertainties and disturbances exist in the actual production which will directly or indirectly affect the control precision,and then affect the final quality of the product.Based on the theory of ADP,this paper studies the robust control of nonlinear systems under various uncertainties and disturbances.This paper mainly develops from two aspects of theoretical research and related application scenarios,and carries out specific analysis and design for specific scenarios.Firstly,considering the robust tracking control problem of uncertain nonlinear systems,the matched/unmatched uncertainties are analyzed and the design idea of corresponding cost function is given.Further,the robust tracking control problem of nonlinear systems with considering unmatched uncertainties is analyzed.An auxiliary system is estabilished for the unmatched uncertainties.Then,a transient tracking error system is obtained through steady and transient analysis,and the robust tracking control strategy can be obtained.Based on the ADP framework,the approximate optimal solution of the robust tracking control problem is obtained.Meanwhile,the robust tracking control strategy is theoretically guaranteed by using Lyapunov stability analysis,and the effectiveness is verified by simulation experiments.In the following,quadrotor aircraft and microgrid system are used as backgrounds to consider uncertainties and design adaptive robust control strategies.For time-varying and coupling uncertainties in a quadrotor aircraft system,a neural-iterative-based robust tracking control strategy is designed.Based on the position and attitude tracking error subsystem,an improved weight updating rule of neural network is proposed to relax the requirement of initial stability control,and an approximate optimal control law is obtained through an iterative algorithm.Finally,considering the time-varying and coupling uncertainties in the actual flight environment,three simulation cases based on linear and nonlinear quadrotor dynamics are given to demonstrate the effectiveness of the control strategy.For the microgrid systems,with the increasing proportion of renewable energy generation,stochastic power generation and dynamic uncertainty bring great challenges to the frequency control of microgrid.In this paper,an intelligent frequency control strategy based on ADP is proposed to adjust the power output of micro-turbine and energy storage system(ESS).In addition,considering the changes of PV power and load demand in a day,the full utilization of PV power and the recycling of ESS can be realized through the proposed regulation strategy.Simulation cases validate the energy-storage-based intelligent frequency control strategy for the microgrid.Compared with PID,fuzzy logic control and linear quadratic regulator(LQR),the superiority of the proposed control strategy is demonstrated.