This article proposes a robust nonlinear position control for permanent magnet stepper motors. We develop a new single-input single-output model that consists of position, velocity, and acceleration using a commutation scheme to lump a system function and an external disturbance into a disturbance. An augmented observer is designed to estimate the position, velocity, acceleration, and disturbance. Because the disturbance refers to external disturbance, acceleration dynamics, and parameter uncertainties, it is difficult to accurately estimate disturbance without the high observer gain. It may result in the degradation of the position tracking performance. The nonlinear controller is then developed using backstepping to suppress the position tracking error using the input-to-state stability property. The key innovation of the proposed method is the design of the nonlinear gain to suppress the position tracking error according to the disturbance estimation error. Thus, the use of the high observer gain to accurately estimate the disturbance can be avoided. The proposed control algorithm was experimentally verified using the PM stepper motor control system and can be easily implemented in real-time using position measurements only.

中文翻译：

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永磁步进电机仅使用位置反馈的非线性增益位置控制

本文提出了一种用于永磁步进电机的鲁棒非线性位置控制。我们使用换向方案开发了一个新的单输入单输出模型，该模型由位置，速度和加速度组成，以将系统功能和外部扰动集中到扰动中。设计了增强的观察器以估计位置，速度，加速度和干扰。由于扰动是指外部扰动，加速度动力学和参数不确定性，因此在没有高观察者增益的情况下很难准确估计扰动。这可能会导致位置跟踪性能下降。然后使用反步法开发非线性控制器，以利用输入到状态的稳定性来抑制位置跟踪误差。该方法的关键创新是设计了非线性增益，以根据干扰估计误差来抑制位置跟踪误差。因此，可以避免使用较高的观察者增益来准确地估计干扰。所提出的控制算法已通过PM步进电机控制系统进行了实验验证，仅使用位置测量就可以轻松地实时实现。