平面多体系统动力学计算机仿真向量键合图法

摘要

为提高平面多体系统动力学计算机仿真的效率及可靠性,提出了相应的向量键合图法.由系统向量键合图模型基本场及结型结构的输入、输出向量间的代数关系,推导出便于计算机自动建立的系统状态方程及运动副约束反力方程的统一公式.根据运动约束关系,将平面运动构件及旋转铰的向量键合图模型组合起来,建立了3-RRR型平面并联机器人机构的向量键合图模型.通过有效的解耦方法,解决了微分因果关系及非线性结型结构给该类机构动力学计算机仿真所带来的代数困难.在此基础上,实现了3-RRR型平面并联机器人机构的计算机自动建模与仿真,验证了所述方法的可靠性及有效性.%To improve the reliability and efficiency of the computer simulation of planar multibody system dynamics,the corresponding vector bond graph method is proposed.From the algebraic relations of input and output vectors in the basic fields and junction structure of the system's vector bond graph model,the unified formulae of the system's state equations and joint's constraint force equations are easily derived automatically by a computer.From the kinematic constraint condition,the vector bond graph model of the 3-RRR planar parallel robot mechanism is established by assembling the vector bond graph model of planar moving rigid body and revolute joint.The effective decoupling method overcomes the algebraic difficulty caused by differential causality and nonlinear junction structure in the computer simulation of the system's dynamics.Based on these,the computer automatic dynamic modeling and simulation of the 3-RRR planar parallel robot mechanism are realized,and the reliability and validity of the method proposed is verified.