基于反正切非线性函数的自抗扰控制

传统扩张状态观测器(ESO)在对系统进行观测时，对系统输出的测量噪声较为敏感，文中构造了一种基于反正切函数的非线性函数以替代ESO中的幂次函数，并给出了由其构成的ESO的一般形式，使用李雅普诺夫函数对观测误差进行了分析；然后，提出了2种基于反正切非线性函数的改进ESO方案，以及基于这2种ESO方案的改进自抗扰控制算法.仿真数据表明，改进的ESO对由输出测量噪声带来的观测噪声有明显抑制，尤其可以对干扰量估计的噪声抑制在很小的范围内，2种改进自抗扰控制算法针对输出带有测量噪声的控制对象均取得较好的控制效果.

An Improved ADRC Based on Nonlinear Arctangent Function

To reduce the observation noise in the traditional extend state observation (ESO) when dealing with the system with output measurement noise,
an ARCTANFAL function was proposed to replace the commonly used FAL function in ESO. The normal form of ARCTANFAL function based ESO was given, whose observation error analysis was conducted by using a Lyapunov function. Besides, two improved ESO using the ARCTANFAL function and two ADRCs based on these two ESOs for the system with output measurement noise were proposed. Simulation results show that these two improved ESOs can minimize the observation noise, especially in the observation of the disturbance, and the two ADRCs also have good performance on dealing with systems with output measurement noise.