This paper aims to propose a novel idea for the modeling and trajectory tracking control of a lower limb rehabilitation robot. A polynomial nonlinear uncertain model is established to deal with the difficulty of accurate modeling for the lower limb rehabilitation robot with complex dynamic characteristics. A high‐order nonlinear disturbance observer (HONDO) is utilized to estimate the lumped disturbance with fast time‐varying and the corresponding observer gain matrix is obtained by H_∞ performance. Then an HONDO‐based composite tracking controller is designed to achieve good tracking performance of the lower limb rehabilitation robot. In addition, all solvability conditions can be directly handled by sum of squares programming, effectively avoiding the calculation problem. Finally, numerical simulations are conducted to verify the validity of the proposed method.

中文翻译：

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基于多项式非线性不确定模型的下肢康复机器人跟踪控制

本文旨在为下肢康复机器人的建模和轨迹跟踪控制提出一个新的思路。建立了多项式非线性不确定性模型，以解决具有复杂动态特性的下肢康复机器人难以精确建模的难题。中的高阶非线性干扰观测器（HONDO）被用来估计与快速时变的集总干扰和由所获得的对应的观测器增益矩阵ħ _∞表现。然后设计基于HONDO的复合跟踪控制器，以实现下肢康复机器人的良好跟踪性能。另外，所有可溶性条件都可以通过平方和编程直接处理，有效避免了计算问题。最后，通过数值模拟验证了所提方法的有效性。