自抗扰控制器的阶次与参数的选取

本文就选择不同阶次的自抗扰控制器时,对系统的控制参数选取进行了研究.结果表明:线性时不变系统的线性自抗扰控制,可等效为一个复合控制系统,其等效反馈补偿器为一超前校正单元串联一积分器;其等效前置滤波器为一滞后校正单元串联一微分器.观测器带宽和控制器带宽的比值,决定着反馈补偿器的最大相位超前角,而频带则决定着最大相位超前角的发生位置.同时,随着自抗扰控制器阶次的增加,补偿器的最大超前校正角也增加.通过对开环系统的频域分析,本文给出了利用该补偿器的频域特性进行自抗扰控制器参数设计的一般步骤,可大幅度减少工程师的反复试验过程,方便工程师应用.

Order and parameter selections for active disturbance rejection controller

We investigate the parameter selection of active disturbance rejection controllers (ADRC) of different orders. For a linear time-invariant system, the linear ADRC can be converted to a composite control system, whose feedback compensator is a phase-lead element in series with an integer and pre-filter is a phase-lag element cascading a differentiator. The ratio of the observer bandwidth to the controller bandwidth determines the maximum phase-lead angle of the feedback compensator, while the frequency band determines the location of the maximum phase-lead angle. In addition, the higher the order of ADRC, the larger the maximum amount of phase-lead angle will be under the same ratio. The practical way of using this method in industrial process is given, which can significantly shorten the trial and error process and facilitate the application for engineers.