Adaptive Position Tracking Control Of Single-Link Flexible Manipulator Based On State Observer

In recent years,with the rapid development of science and technology and industrialization,flexible manipulators have been widely used in the fields of machinery manufacturing and aerospace due to their low power consumption,lightweight,and fast movement speed.However,due to the physical characteristics of the flexible manipulator itself,the parameters of the established dynamic model are very complex,and it is difficult to achieve high-precision tracking control of its position.The following study has been conducted in this paper based on a single-link flexible manipulator.(1)In this paper,the flexible manipulator is approximated as a Euler–Bernoulli beam for modeling analysis.The partial differential equation dynamics model of the flexible manipulator is established by applying the Hamiltonian principle.The hypothetical mode method is used to reduce the dimension of the partial differential equation dynamic model of the flexible manipulator,and the ordinary differential equation dynamic model is obtained and the expression of the state space equation is derived.According to the state space expression of the flexible manipulator,a dynamic model of the flexible manipulator reflecting the higher-order modes of the Euler–Bernoulli beam is established.(2)This paper focuses on the disturbance effects caused by high-order modes of flexible manipulator on position tracking control.Based on the dynamic model of a flexible manipulator using the Euler-Bernoulli beam high-order mode,a state observer is designed to observe the high-order mode variables.An adaptive control method for position output feedback tracking of flexible manipulator is proposed.Simulation analysis is conducted using MATLAB/Simulink,and the effectiveness and feasibility of the output feedback tracking control are verified by comparing it with traditional adaptive control methods.(3)During the operation of a flexible manipulator system,it is often subject to various uncertain factors,resulting in large position tracking errors and even causing oscillations and structural damage to the system.In order to improve the safety and robustness of the flexible manipulator system,this paper studies the constrained state of the position tracking control problem of the flexible manipulator,and proposes an adaptive control method for position output feedback tracking based on obstacle Lyapunov functions.By using both constant and time-varying logarithmic obstacle Lyapunov functions to constrain the output of the flexible manipulator system,two controllers are designed and compared through simulation analysis using MATLAB/Simulink software.The feasibility and effectiveness of the feedback controller based on time-varying logarithmic obstacle Lyapunov functions in the position tracking of the flexible manipulator are verified.(4)Research was conducted on the issue of reduced model accuracy due to parameter simplification in the state space equation of a flexible manipulator.An integrated simulation experimental platform was constructed using Adams virtual prototyping simulation software combined with MATLAB/Simulink,and a feedback controller based on the timevarying logarithmic barrier Lyapunov function was designed and simulated to verify the effectiveness of the controller on the actual control results of the flexible manipulator.