基于干扰观测的气动调节阀定位系统设计

Design of Pneumatic Regulating Valve Positioning SystemBased on Interference Observation

阀门定位控制器作为调节阀的控制核心,决定着气动调节阀的调节精度和响应速度,在调节阀的运行中发挥着不可替代的作用。针对气动阀门定位系统的非线性、易受气源质量影响和模型不准确等问题,设计了一种基于干扰观测的气动调节阀定位系统。首先,建立气动调节阀定位系统的数学模型。然后,利用非线性干扰观测器估计模型不确定性和外部环境干扰,将干扰观测信息应用于反步控制器设计,以较好地处理气动调节阀系统在工业过程中受到的集总扰动(包括外界干扰、未建模动态和模型参数摄动等)影响。最后,使用Matlab对气动调节阀定位系统进行仿真,并对仿真结果进行了相应的数据分析。仿真结果和数据分析结果表明,非线性扰动观测器能够准确估计系统集总扰动。同时,与积分反步法的比较结果表明,所用控制方法的轨迹跟踪误差的均方根值更小、跟踪效果更好。在所设计控制器作用下,气动阀的实际阀位能够准确跟踪期望阀位轨迹。

As the control core of the regulating valve, the valve positioning controller determines the regulation accuracy and response speed of the pneumatic regulating valve and plays an irreplaceable role in the operation of the regulating valve.Aiming at the problems of the pneumatic valve positioning system nonlinearity, the susceptibility to the quality of the gas source and the inaccuracy of the model, a pneumatic regulating valve positioning system based on interference observation is designed.Firstly, the mathematical model of the pneumatic regulating valve positioning system is established.Then, the nonlinear disturbance observer is used to estimate the model uncertainty and external environmental disturbances, and the disturbance observation information is applied to the backstepping controller design, which can better deal with the effects of the aggregate disturbances (including external disturbances, unmodeled dynamics, and model parameter uptake, etc.) of the pneumatic regulating valve system in the industrial process.Finally, the pneumatic regulating valve positioning system is simulated using Matlab, and the simulation results are analyzed with corresponding data.The simulation results and data analysis results show that the nonlinear disturbance observer can accurately estimate the aggregate disturbances.Meanwhile, the comparison results with the integral backstepping method show that the root-mean-square value of the trajectory tracking error of the used control method is smaller and the tracking effect is better.Under the action of the designed controller, the actual valve position of the pneumatic valve can accurately track the desired valve position trajectory.