Servo system adaptive sliding mode control method based on extended-state observer

Abstract

A servo system adaptive sliding mode control method based on an extended-state observer comprises establishing a servo system model, initializing a system state and a control parameter, performing approximate compensation on a saturation link, designing a non-linear extended-state observer, determining an observer parameter by utilizing a pole placement method, and designing an adaptive sliding mode controller. The extended-state observer is designed and is used to estimate the system state and uncertain items comprising system friction and an external disturbance, and the observer gain parameter is determined through adoption of the pole placement method; and the adaptive sliding mode controller is designed, a system tracking error is guaranteed to be rapid and stable and to converge to zero, and rapid and stable control of a servo system is finally achieved. The problem that the system friction and other external disturbances are unmeasured is solved, a non-linear saturation link influence existing in the system is compensated, a buffeting problem existing in an ordinary sliding mode method is improved, robustness of the system is enhanced, and the system can rapidly and stably track a desired signal.

Description

technical field [0001] The invention designs an adaptive sliding mode control method of a servo system based on an extended state observer, which is suitable for controlling some servo systems with nonlinear saturation links and uncertain external disturbance factors such as friction. Background technique [0002] Servo System (Servo System) is a servo system that uses electric motors as power drive components, and is widely used in various fields such as flight control and fire control. However, there are nonlinear links such as friction and dead zone in most servo systems, coupled with the limitation of saturation limit, it will not only affect the tracking accuracy and dynamic characteristics of the system, but even lead to system instability in severe cases, thus affecting normal operation of the system. Among them, if the adjustment range of the system actuator is limited, and the amplitude of the control signal is too large, nonlinear saturation characteristics will b...

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Problems solved by technology

[0005] The sliding mode variable structure control method is fully adaptive and robust. Once it enters the sliding mode state, the transition of the system state will no longer be affected by the change of system parameters and external disturbances, but the general sliding mode control, in the system state When reaching the sliding mode surface, it will cross back and forth on both sides of the equilibrium point to approach the equilibrium point, resulting in chattering problems

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