基于噪声抑制的电液位置伺服系统自抗扰控制方法

Active Disturbance Rejection Control of Electro-Hydraulic Position Servo System Based on Noise Suppression

测量噪声对扩张状态观测器带宽的限制是影响电液伺服系统自抗扰位置控制器性能的关键问题。为此,提出了一种基于噪声抑制扩张状态观测器的改进自抗扰控制方法。建立电液伺服系统非线性模型,通过坐标变换构造链式积分器结构,明确电液伺服系统“总扰动”。引入低通滤波器抑制高频测量噪声,利用滤波后的位置信号构建改进型扩张状态观测器,补偿滤波器导致的相位滞后,分离状态反馈与扰动估计,增加新的扰动估计调节参数,调和观测器高带宽、高估计性能与噪声放大间的矛盾。采用李雅普诺夫稳定性理论证明了闭环系统的稳定性。仿真与试验结果表明,在系统受扰状态下,与传统LADRC相比,本文所提出控制方法扰动抑制能力更强,位置跟踪精度更高,为自抗扰控制器的工程应用提供了参考。

The limitation of measurement noise to the bandwidth of the extended state observer is a key problem that affects the performance of active disturbance rejection position controller of electro-hydraulic servo system.Therefore,an improved active disturbance rejection control method based on noise suppression extended state observer was proposed.The nonlinear model of the electro-hydraulic servo system was established,the chain integrator structure was constructed by coordinate transformation,and the“total disturbance”of the electro-hydraulic servo system was defined.A low-pass filter was introduced to suppress the high-frequency measurement noise,and the improved extended state observer was constructed by using the filtered position signal to compensate for the phase lag caused by the filter,separate the state feedback from the disturbance estimation,add new disturbance estimation adjustment parameters,and reconcile the contradiction between the high bandwidth and high estimation performance of the observer and the noise amplification.The controller was designed for a typical valve-controlled symmetrical cylinder electro-hydraulic servo system and the closed-loop system stability was analyzed by using Lyapunov stability theory.The control method required few tuning parameters which was easy for engineering practice.Simulation and test results showed that compared with traditional LADRC,the proposed control method had stronger disturbance suppression ability and higher position tracking accuracy under the disturbed state,which provided a reference for the engineering application of ADRC.