基于静力学分析的运动副摆放位置对并联机构的影响

Effect of Different Positions of Kinematic Pairs on Parallel Mechanism

目的分析芯片封装"两转一移"柔性并联机构3-SPR和3-RPS的运动特性和静力学特性,并比较优劣。方法运用螺旋理论对运动副不同分布的3-SPR和3-RPS机构进行运动学分析,并运用螺旋分析法求解机构的等效约束力及驱动力,得出在外载荷下机构的等效平衡方程;通过Matlab软件编程进行理论计算,运用Solid Works软件进行建模及Adams静力学仿真,以验证理论计算的正确性,并运用有限元分析软件进行仿真验证。结果运动副摆放位置不同,其约束力对3-SPR和3-RPS机构产生的影响也不同,3-SPR并联机构的约束力作用于定平台,相对于3-RPS并联机构的约束力作用于动平台,其约束力所产生的扰动更小,支链的变形更小。结论 3-SPR机构具有更好的稳定性,在芯片封装、压印等高精度包装工程应用中可满足更高的精度要求,为柔性机构的研究提供了理论参考。

The kinematics and statics properties of the ＂2T1R＂ 3-SPR and 3-RPS flexible parallel mechanisms for the chip packages were analyzed and compared. The screw theory was applied to analyze kinematics. For the statics analysis, the equivalent binding force and driving force was analyzed according to screw analysis approach, and the equivalent balance equation was listed under external load. The theory was calculated using Matlab software. Through modeling by Solidworks and Adams kinematics simulation, the correctness of the theoretical calculation was verified. Our results showed that the binding force have different impact on the 3-SPR and 3-RPS parallel mechanism since the kinematic pairs position was different. When the 3-SPR parallel mechanism restricts the binding force for the fixed platform, there was less disturbance by the binding force and less deformation of the branched chain, comparing to these when the 3-RPS parallel mechanism restricts the moving platform. 3-SPR parallel mechanism showed better stability and better mechanical properties, which can satisfy the higher precision application in the field of chip packaging, embossing and other high precision engineering. Our study provided a theoretical reference to the research of flexible mechanism.