A novel immersion and invariance (I&I) angular velocity observer is presented for the attitude tracking control of a rigid body with the lack of angular rate. Global exponential convergence of angular velocity estimate errors are guaranteed by an innovative filter design for the estimates' Euclidean norm. The proposed method requires fewer filter states compared with existing I&I angular velocity observer designs, which achieves a simpler closed‐loop structure (dynamic reduction). The observer synthesis and convergence are independent of the control torque, which leads to much convenience in establishing “separation property” when combining a proportional‐derivative attitude tracking controller driven by angular velocity estimates. A rigorous stability analysis is provided to ensure the (almost) global asymptotic convergence of the overall closed‐loop tracking errors, and several numerical simulations are carried out to demonstrate the effectiveness of the combined implementation of proposed angular velocity observer and full‐state feedback attitude tracking controller.

中文翻译：

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通过沉浸式和不变角速度观测器对刚体姿态进行输出反馈跟踪控制

提出了一种新颖的浸入和不变（I＆I）角速度观测器，用于缺乏角速度的刚体的姿态跟踪控制。创新的滤波器设计可确保角速度估计误差的全局指数收敛，该设计适用于估计的欧几里得范数。与现有的I＆I角速度观测器设计相比，该方法所需的滤波器状态更少，从而实现了更简单的闭环结构（动态降低）。观察者的合成和收敛与控制转矩无关，这在组合由角速度估计驱动的比例-导数姿态跟踪控制器时，在建立“分离特性”方面带来了很多便利。