基于扩张状态观测器的连续体机械臂分数阶滑模控制

Extended state observer based fractional sliding-mode control strategy for continuum robot arms

中文关键词  连续体机械臂  扩张状态观测器  分数阶滑模控制  模型不确定性  外部干扰

英文关键词  continuum robot arms  extended state observer  fractional sliding-mode control  model uncertainties  external disturbance

中文摘要

      连续体机械臂在非结构化环境中具有广泛的应用前景, 但由于其动力学模型存在强非线性、模型不确定和 外部干扰等, 现有控制算法抗扰性能有限. 本文提出了一种基于扩张状态观测器的分数阶滑模控制策略, 用于连续 体机械臂的末端轨迹跟踪. 该控制器基于连续体机械臂动力学模型设计, 由3个部分组成: 第1部分是非线性动态反 馈线性化; 第2部分设计了扩张状态观测器, 用于估计和补偿外部干扰和模型不确定性; 第3部分设计了分数阶滑模 控制器以实现闭环控制, 进一步给出了扩张状态观测器和闭环系统的稳定性证明. 通过对比不同控制策略对给定 阶跃角度、正弦角度和圆轨迹的跟踪效果, 验证了所提出的控制策略在轨迹跟踪和外部干扰与模型不确定性扰动 抑制方面优于其他典型优化控制器, 这对连续体机械臂的精确控制提供了切实可行的解决方案.

英文摘要

      Continuous robot arms have broad prospects in unstructured environments, but existing control algorithms have limited disturbance rejection performance due to strong nonlinear dynamics, model uncertainties, and external disturbances. This paper proposes a fractional sliding mode control strategy based on an extended state observer for end-effector trajectory tracking of continuous robot arms. The controller is designed based on the dynamic model of the continuous robot arms and consists of three parts. The first part is nonlinear dynamic feedback linearization, the second part designs an extended state observer to estimate and compensate for external disturbances and model uncertainties, and finally, a fractional sliding mode controller is designed to achieve closed-loop control. Furthermore, stability proofs for the extended state observer and the closed-loop system are provided. By comparing the tracking performance of different control strategies for given step angles, sine angles, and circular trajectories, the proposed control strategy is validated to be superior to other typical controllers in terms of trajectory tracking and suppression of external disturbances/model uncertainties. This provides a practical and feasible solution for precise control of continuum robotic arms.