This brief proposes a tuning methodology for proportional-resonant (PR) controllers by using the design philosophy of the Ziegler–Nichols forced oscillation method. Unlike such related methods that are usual for proportional–integral–differential design, and those that have been recently proposed for PR controllers, the method in this brief is not restricted to plants whose Nyquist diagram crosses the negative real axis. It involves a feedback experiment with an adjustable phase relay, which allows the identification of the most appropriate point of the frequency response for each class of plants. The proposed method, which also includes tuning formulas that provide appropriate stability margins for each class of plants, is analyzed in detail for three examples, showing its wide applicability.

中文翻译：

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调整比例谐振控制器的广义强迫振荡方法

本摘要通过使用Ziegler-Nichols强制振荡方法的设计原理，为比例谐振（PR）控制器提出了一种调整方法。与比例-积分-微分设计中常用的此类相关方法以及最近针对PR控制器提出的此类方法不同，本摘要中的方法不限于奈奎斯特图与负实轴交叉的设备。它涉及带有可调相位继电器的反馈实验，该实验可以确定每类植物的频率响应的最合适点。所提出的方法，其中还包括为每类植物提供适当稳定性裕量的调整公式，针对三个示例进行了详细分析，显示了其广泛的适用性。