Research And Application Of Performance Control For Several Kinds Of Nonlinear Systems

From the perspective of the development of control system theory,the nonlinear system control has been favored by the majority of researchers and has achieved fruitful results.Because most of the control systems in production and life belong to nonlinear systems,the research on the performance and stability control of nonlinear systems is particularly important in the field of control and the application of engineering practice.There are many uncertain factors and unknown disturbances in the system itself,which makes the design of the controller more difficult.Based on this,in order to improve the control performance of nonlinear system,the following contents are studied:Firstly,although the traditional finite time stability control can ensure the convergence of the system in a finite time,the convergence time of the system in a strictly feedback nonlinear system is generally related to the initial state,so the concept of fixed time control is introduced.Based on the inversion algorithm and combined with the fixed time tracking controller,the coordinate transformation is given first,the virtual control law is designed,and the actual controller is designed in the last step.The simulation results show that the strict feedback nonlinear system with uncertainties is convergent and stable in the global range,and all the signals in the closed-loop system are bounded.Second,to contain the structure of affine nonlinear pure scheduled performance control problem of feedback systems,using the Lyapunov stability principle and the footwork,pure feedback to nonlinear system as the research object,because the system contains the affine structure,and the system still exist in the unknown parameters,so it will adopt a new coordinate transformation and design appropriate adaptive law.The designed adaptive law can accurately and quickly estimate the unknown parameters and stabilize the system by using predetermined performance control.The results show that the scheme not only ensures the boundedness of the closed-loop system,but also greatly improves the accuracy of the tracking error.Finally,in order to verify the effectiveness of the predetermined performance control scheme of non-affine nonlinear pure feedback system,based on the BOOST circuit state model,the controller generally needs to operate in a discontinuous state,which may cause oscillation.According to the given synchronous BOOST circuit topology,it is converted into equation of state.The simulation results show that by applying the theoretical results to the practical model of BOOST circuit,the proposed performance control algorithm can effectively suppress the system vibration and has certain anti-interference effect.Therefore,the predetermined performance control scheme can be effectively applied in the production practice of some societies.