组合柔性机械臂动力学模型参数识别

Parametric Identification of Dynamic Model of Assembled Flexible Manipulator

将柔性机械臂做成组合结构,利用结合面摩擦效应抑制柔性机械臂的振动。用单根叠层组合柔性臂与实体柔性臂的自由振动对比试验验证组合柔性臂具有优良的抑振性能。用弹簧摩擦副双折线模型和三次非线性弹性力模型建立组合柔性臂的动力学模型。根据组合柔性臂有限元仿真激振试验数据,确定组合柔性臂的形函数和动态恢复力滞迟回线。用动能等效原理、滞迟回线分解法和最小二乘法确定组合柔性臂的动力学模型参数。在Simulink平台上,编制弹簧摩擦副恢复力计算模块,解决含有记忆环节的柔性臂非线性微分方程的数值求解问题。经试验验证,用该模型参数识别方法确定的动力学模型能较准确地反映组合柔性机械臂的动力学性质,为组合柔性机械臂动力学建模、减振性设计提供有效方法。

In order to restrain the vibration of flexible manipulator, friction damping of assembled flexible link can be used to restrain the vibration of flexible manipulator. The contrast experiment with solid flexible link indicates that assembled flexible link has effective vibration-restraining capability. The dynamic model of assembled flexible link is built with an equivalent mass, a nonlinear spring, a damper and a spring-slider. According to the data obtained from FEA simulation of forced vibration of assembled flexible link, its shape function and reaction force hysteresis curve are determined. The dynamic model parameter of assembled flexible link is determined according to kinetic energy equivalence principle, analysis of reaction force hysteresis curve and nonlinear least-squares solution. In addition, S-function block is written in M-file to compute spring-slider. Finally, the simulink model is created according to the dynamic model. The response of free vibration from simulation is consistent with experiment. This method provides an effective way for dynamics modeling and vibration -damping design of assembled flexible link.