为了改善高速空间并联式坐标测量机的动力学性能,将虚拟样机技术应用于该测量机的弹性动力学优化设计中。协同利用CAD、CAE和可视化虚拟样机技术,建立高速空间并联式坐标测量机的刚柔耦合虚拟样机,分别考察动平台质量与驱动杆轴径的变化对测量机运动输出误差及驱动杆最大动应力等动力学行为的影响规律,并据此对这些参数进行优化设计,得到测量机动平台质量为80.85 kg,驱动杆轴径为44 mm。仿真结果表明,经过优化设计,测量机驱动杆最大动应力降为17.5 MPa,运动输出误差也明显小于优化设计前,测量机的动力学特性得到明显改善。
In order to improve dynamic characteristics of high-speed spatial PCMM (parallel coordinate measuring machine), the virtual prototype technology was applied to the elastodynamics optimization design of PCMM. Integrating CAD, CAE and visual technologies, the rigid-flexible virtual prototyping of PCMM was built. The influence law of the mass of moving platform and the diameter of driving limbs on the dynamic behaviors, including kinematics output response and maximum dynamic stress of driving limbs were discussed. On these grounds, the mass of moving platform and the diameter of driving limbs were optimized. The optimal results, which include the mass of moving platform of 80. 85 kg and the diameter of driving limbs of 44 mm, were obtained. The simulation results showed the maximum dynamic stress of driving limbs were decreased to 17.5 MPa, the kinematics output response were also reduced, so that the obvious improvement of the dynamics characteristics for PCMM was realized, and the powerful theoretical basis and method were provided.