冲击激励下变结构超长大柔性机械臂混沌振动机理辨析及控制策略研究

Complex nonlinear dynamic behaviors exist in the ultra-long boom of concrete pump truck. Mechanism analysis and control strategy of chaotic vibration in ultra-long flexible manipulator under changing postures and shock excitations are the key problems. Considering such nonlinear factors as the unsteady shock of concrete transportation, the flexibility of ultra-long manipulator, the non-smoothness of joint dry friction and the non-continuous stiffness of steel/carbon fiber combined manipulator, time-domain modeling and stability analysis of ultra-long flexible manipulator will be carried out based on the obtained research results about linear vibration control of manipulator under typical postures. Mechanism analysis of chaotic vibration in ultra-long flexible manipulator under changing postures and shock excitations will be analyzed and then the parameter condition and evolution rule of the system will be discussed from two aspects of numerical simulation and experimental observation. According to whether chaotic characteristics exist or not, control strategy of nonlinear vibration in ultra-long flexible manipulator under changing postures and shock excitations will be proposed using the radical basis function network or mixed eural fuzzy logic algorithm respectively. Furthermore, the configuration scheme of sensor and actuator will be designed and the actuators of boom cylinder and rotary engagement will be improved. Finally, the verification experiments of nonlinear vibration control will be carried out based on the establishment of acquisition and control test system. The research results will provide important theoretical and practical support for the improvement of ultra-long manipulator’s dynamical characteristics and the design of longer manipulators in the future.

泵车超长臂架蕴含着复杂的非线性动力学行为，深入辨析冲击激励下变结构超长大柔性机械臂混沌振动机理并提出振动控制策略是研究的关键。本项目在典型姿态机械臂线性振动控制已有成果基础上，考虑混凝土输送冲击非稳态、超长臂架大柔性、多关节干摩擦非光滑、钢质/碳纤维臂架刚度非连续等因素，开展超长机械臂时域法建模和稳定性分析；从数值仿真和试验观测两方面辨析冲击激励下变结构大柔性机械臂混沌振动机理，探讨系统存在混沌振动的参数条件和演化规律；根据振动是否具有混沌特性，分别采用径向基函数网络、混合神经模糊逻辑推理算法，提出相应的冲击激励下变结构大柔性机械臂非线性振动控制策略；设计传感器/作动器配置方案，改进臂架油缸、回转啮合作动器，搭建机械臂非线性振动控制试验系统开展试验验证，实现冲击激励下变结构大柔性机械臂非线性振动的有效控制。成果可为超长机械臂装备动力品质的提升及更长机械臂的研制提供重要的理论与应用支撑。

超长臂架泵车在施工作业中易产生较大幅度的臂架末端空间振动，严重影响泵车臂架的施工安全、定位精度与结构寿命。本项目以长臂架混凝土泵车的柔性臂架结构为对象，在典型姿态机械臂线性振动控制已有成果基础上，考虑混凝土输送冲击激励的非稳态、超长大柔性臂架的大变形、臂架多关节干摩擦的非光滑、钢质/碳纤维臂架组合刚度的非连续等诸多非线性因素，建立了长机械臂时域法动力学模型，从数值仿真和试验观测两方面开展了冲击激励下变结构超长大柔性机械臂混沌振动机理辨析，探讨了机械臂系统出现混沌振动状态的参数（如机械臂姿态、相邻机械臂的相对转动速度、机械臂关节摩擦参数、混凝土泵送排量等）取值范围和演化规律。开展了冲击激励下变结构超长大柔性机械臂混沌控制策略研究，提出了相应的冲击激励下变结构大柔性机械臂非线性振动控制策略，设计了传感器/作动器配置的优化方案，并改进了臂架作动液压系统及回转啮合作动液压系统，搭建了非线性振动控制实验平台，完成了冲击激励下变结构超长大柔性机械臂非线性振动的有效抑制，综合抑振效果达到60%左右，实现了冲击激励下变结构超长大柔性机械臂混沌振动机理辨识与控制策略的理论突破和实验验证。项目研究期间发表期刊论文8篇，其中SCI收录论文5篇，中文论文3篇，已接收待刊印1篇；授权发明专利14项，其中欧专局发明专利1项、中国发明专利13项；申请中国发明专利12项；获得湖南省科技进步二等奖1项；培养毕业硕士生6名。项目研究成果已经在中联重科股份有限公司的混凝土泵车产品上开展工程化应用尝试并取得了积极效果，这不仅对未来更长臂架混凝土泵车的研制和现有超长臂架混凝土泵车的动力品质提升具有重要的理论和应用价值，而且对具有类似机械臂结构的高端装备（例如，长臂架举高消防车、长臂架高空作业平台、航天器柔性臂等）的振动控制具有重要的参考价值。