Auto-coupling PID Control Principles For A Class Of Non-affine Pure-feedback Nonlinear System

Non-affine pure feedback nonlinear systems are widely used in the field of industrial control.There are great theoretical significance and application value in studying the control problem of such systems.Aiming at the control problem of a class of non-affine nonlinear pure feedback system,a new cooperative control method of Auto Coupling Proportional Integral Differential(ACPID)is used.The main research work of this paper is as follows:1)All the complex factors in non-affine pure feedback nonlinear systems such as known or unknown dynamic,internal uncertainty,time-varying uncertainty,external disturbance are defined as the total disturbance.Any complex unknown non-affine pure feedback nonlinear system is mapped to the integral series of unknown linear system,which purpose is to dilute the concept of complex nonlinear systems with linear system classification and unify the control theory method of complex nonlinear system and linear system;2)According to the integral series unknown linear system,the controlled error system under the total disturbance reverse excitation is established.According to the ACPID control theory,design the ACPID controller,establish the ACPID closed-loop control system,analyze the robust stability and anti-total disturbance robustness of the ACPID control system;3)In order to avoid overshooting and oscillation caused by excessive integral control force and proportional control force during dynamic period,an adaptive velocity factor model based on absolute error change rate is studied,which effectively solved the contradiction between dynamic quality and steady-state performance;4)In order to verify the ACPID control method is effective,a class of pure feedback non-affine nonlinear complex system control problems for a series of simulation experiments,the simulation results show the effectiveness of the ACPID control method.Compared with the existing control theory method,the ACPID control theory method not only has faster response speed,high steady precision,strong ability to resist disturbance.Moreover,the ACPID controller has simple structure and only one speed factor needs stabilization,which is convenient for practical application.The main innovation points of this paper are as follows:1)By introducing the concept of total disturbance,the essential difference between the control of arbitrary nonlinear system and linear system is diluted;2)According to the idea of ACPID control theory,the control theory method of nonlinear system and linear system is unified;3)The PID tuning rule based on speed factor is established,which effectively solves the problems of poor robustness of PID gain and poor robustness of anti-disturbance.