旋量键合图在并联机构动力学建模中的应用

Screw Bond Graph in the Application of the Parallel Mechanism Dynamics Modeling

旋量键合图将旋量理论与键合图相结合,兼具了旋量理论描述空间并联机构简洁、直观及键合图多能域建模统一、规范的特点。对空间并联机构基本组成单元——构件和运动副,利用旋量键合图,构建动力学模型,并进行模块化处理。在此基础上,调用单元模块,就可建立与可视化的机构一一对应的并联机构旋量键合图模型,按照规则化推导方法,得到适用于现代控制理论的空间并联机构状态方程。以曲柄滑块机构及空间3-UPS/S并联机构为研究对象,验证旋量键合图模块化建模的可行性,给出空间并联机构具有通用性的规则化动力学建模过程,并且进一步分析空间3-UPS/S并联机构匀速及加速运动状态下驱动力、支链约束反力变化规律。这种建模方法的应用为后续构建机器人系统全局动力学模型及控制研究奠定基础。

Screw bond graph combines screw theory with bond graph. It has characteristics of screw theory and bond graph which are simple and intuitive to describe the spatial mechanism, and unified and standard to build the multi-energy domain model. Dynamic models of bodies and kinematic pairs are built by screw bond graph, and then modularized. By using the modules, the spatial parallel mechanism model can be established and the state-space equations which are suitable for modem control theory can be obtained. The slider-crank mechanism and spatial 3-UPS/S parallel mechanism are taken as examples. By using the above method, it is given that the dynamic modelling process of the spatial parallel mechanism which is common and regularization. The motion rules of driving and constraining force under the states motion of uniform and accelerated are analyzed, which lays the foundation for building global dynamics model of the robot system and subsequent control research.