基于运动学、刚度和动力学性能的并联机构有序递进三级优化设计及其应用

Three-level Orderly Proceeding Optimization Design and Its Applications for Parallel Mechanisms Based on Kinematics,Stiffness and Dynamics

提出一种基于运动学、刚度和动力学性能的并联机构有序递进三级优化策略,即分别应用遗传算法(GA)、粒子群算法(PSO)、差分进化算法(DE)三种智能算法,以工作空间性能和运动/力传递性能为目标的尺度参数优化方法,又在优化尺度参数基础上,以机构承载刚度和整体刚度为目标进行构件截面参数优化,再在优化尺度参数和截面参数基础上,以动力学灵巧度和能量传递效率为目标进行构件质量参数优化,从而使得机构的尺度、截面及质量参数达到最优。以一种零耦合度三平移一转动(SCARA)并联操作手为例,运用矢量法建立了并联操作手的运动学模型,通过工作空间性能和运动/力传递性能两个运动学指标,优化其尺度参数;运用虚拟弹簧法得到该并联操作手的刚度模型,通过对三维模型的参数识别得到其柔度矩阵,并分析了承载刚度、整体刚度两个刚度性能指标,优化了构件的截面参数;利用动力学普遍方程导出了该并联操作手的动力学模型,通过动力学灵巧度和能量传递效率两个动力学性能指标,优化了构件的质量参数。最终,该并联操作手的运动学、刚度和动力学综合性能达到最优,也得到了一些尺度、截面及质量参数的设计准则。

A three-level orderly proceeding optimization methodology was proposed based on kinematics,stiffness and dynamics of PM.The three intelligent algorithms of genetic algorithm(GA),particle swarm algorithm(PSO)and differential evolution(DE)were applied to optimize the dimensional parameters,sectional parameters and mass parameters respectively.Firstly,optimization of the dimensional parameters was aiming at the workspace performance and motion/force transmission performance.Secondly,on the basis of the dimension parameter optimization,the sectional parameters of the components with the objective of the bearing stiffness and overall stiffness of the mechanisms were optimized.Finally,on the basis of the dimensional parameters and sectional parameter optimizations,the mass parameters of the mechanisms were optimized with the objective of dynamics dexterity and energy transmission efficiency.A zero-coupling SCARA PM was used as an example to illustrate the optimization procedure.Firstly,the kinematics model of the PM was established by using vector method,and the dimensional parameters were optimized through the workspace performance and motion/force transmission performance.Secondly,the stiffness model of the PM was obtained by using the virtual spring method,and the flexibility matrix was obtained through the parameter identification of CAD model.Then,the dynamics model of the PM was derived by using the general dynamics equation,and the mass parameters of the components were optimized through the dynamics dexterity and energy transmission efficiency.Thus,the comprehensive performances of kinematics,stiffness and dynamics of the PM reached.Meanwhile,some design criteria of dimensional,sectional and mass parameters were obtained.