混合结构液压柔性臂机器人的振动控制方法研究

With the applications of the flexible robots with light weigth and long arm structure becoming much wider in practice, the research on the vibration control issue of the flexible arm during its movement has become one of the most important research issues. Moreover, in comparision to the motor-driven system, the hydraulic flexible systems have more complex dynamics and the control problem is more difficult. Currently most of the existing research on hydraulic flexible robot aims at the systems with one or two revolute link(s), while those with more complex structures are rarely considered. In this project, we attempt to take the hydraulic flexible robot with the typical hybrid structure with two revolute links and two prismatic links as the object to study. With analysis on the flexible multi-body dynamics of such a robot, the vibration control method will be studied during its trajectory tracking.. During the study of this project, the research contents include the flexible dynamics modeling and simulation of the hydralically driven arm with combined-structure, design of online observer for the flexible mode variables, trajectory planning methed based on the excitation force optimization, robust vibration control of trajectory tracking considering parameters uncertainty. With combination with the flexible multi-body dynamics of the arm and the electro-hydraulic servo system, the completed dynamics of the flexible hydraulic driven robot with combined structure will be established. With the online estimation oberver, the issue of the difficulty of some flexible mode variables measurement will be solved. With the combination of trajectory planning and trajactory tracking, the motion control with vibration elimination for the flexible robot with hybrid structure and parameters uncertainty will be achieved.

轻质长臂结构的弹性臂机器人在实际系统中应用越来越广泛，其运动中的振动控制问题也已成为国内外研究的热点之一。而液压柔性臂相对于电机驱动的柔性臂而言，动力学耦合性更强，控制难度更大。目前关于液压柔性臂的研究主要是单节和双节液压折叠臂，而对于复杂结构的液压柔性臂研究较少。本课题拟采用折叠-伸缩混合结构的液压柔性臂为对象，相对于以往单一构型的液压柔性臂，其柔性变形更复杂，耦合性更强，不确定因素更多，分析与控制更困难。. 在本课题的研究过程中，拟主要对混合式液压柔性臂的动力学建模、柔性模态变量在线估计器设计、基于最小化激振力的抑振轨迹规划、考虑不确定性的柔性臂鲁棒控制等问题进行研究。通过伸缩臂分段建模结合电液伺服模型建立混合结构柔性液压臂的完备动力学，通过在线估计器解决实际系统中部分柔性状态变量难以获取的问题，通过轨迹规划和跟踪控制相结合实现参数不确定性的复杂柔性臂控制问题。

具有平移-旋转混合结构的弹性臂机器人在实际系统中有着广泛的应用前景，本项目针对机器人运动过程的振动控制问题开展研究，对混合结构柔性臂的动力学建模、状态在线估计、抑振轨迹规划、抑振跟踪控制等方面开展研究，相对于单一构型的柔性臂系统，本项目的研究对象其柔性变形更复杂，耦合性更强，不确定因素更多，分析与控制更困难。. 针对动力学建模问题，采用假设模态法建立了三段式伸缩臂（基础段、重叠段、伸出段）的形变方程，以柔性多体动力学递推列式建立了柔性臂动力学模型，利用电液伺服系统理论推导了液压驱动系统模型，联合形成其完备动力学模型。针对模态变量在线估计问题，提出了基于滑动傅里叶变换的振动分量分析方法，设计了模糊逻辑自适应卡尔曼滤波器，实现了柔性臂末端状态的完整估计。针对抑振轨迹规划问题，采用非均匀插值点时刻实现多项式轨迹初始化，通过粒子群算法优化插值点位置增量，采用样条插值实现了新运动轨迹的拟合。针对抑振跟踪控制问题，通过在线学习策略对输入整形的参数进行自适应修正，构成了自适应输入整形控制器，实现了柔性臂运动轨迹的抑振控制。通过搭建ADAMS、AMESim 与Matlab联合仿真平台，构建混合结构柔性臂物理实验系统，项目研究过程中所提出的模型和方法均得到了有效的验证。. 本项目通过研究具有折叠-伸缩混合臂式复杂结构的液压柔性臂的振动控制方法，实现了具有复杂结构的柔性机械臂的分析，结合柔性机器人振动控制的相关理论方法，解决了柔性臂末端的振动抑制问题，为今后复杂结构柔性臂机器人和大型工程机械的应用提供了理论依据和技术支撑。