The extended state observer (ESO) plays an important role in the design of feedback control for nonlinear systems. However, its high-gain nature creates a challenge in engineering practice in cases where the output measurement is corrupted by non-negligible, high-frequency noise. The presence of such noise puts a constraint on how high the observer gains can be, which forces a trade-off between fast convergence of state estimates and quality of control task realization. In this work, a new observer design is proposed to improve the estimation performance in the presence of noise. In particular, a unique cascade combination of ESOs is developed, which is capable of fast and accurate signals reconstruction, while avoiding over-amplification of the measurement noise. The effectiveness of the introduced observer structure is verified here while working as a part of an active disturbance rejection control (ADRC) scheme. The conducted numerical validation and theoretical analysis of the new observer structure show improvement over standard solution in terms of noise attenuation.

中文翻译：

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用于测量噪声下有源抗扰控制应用的级联扩展状态观测器

扩展状态观测器 (ESO) 在非线性系统的反馈控制设计中起着重要作用。然而，在输出测量被不可忽略的高频噪声破坏的情况下，其高增益特性给工程实践带来了挑战。这种噪声的存在限制了观察者增益的高低，这迫使在状态估计的快速收敛和控制任务实现的质量之间进行权衡。在这项工作中，提出了一种新的观察器设计，以提高存在噪声时的估计性能。特别是，开发了一种独特的 ESO 级联组合，能够快速准确地重建信号，同时避免测量噪声的过度放大。在作为自抗扰控制 (ADRC) 方案的一部分工作时，这里验证了引入的观测器结构的有效性。对新观测器结构进行的数值验证和理论分析表明，在噪声衰减方面优于标准解决方案。