平面连杆机构运动精度可靠性及灵敏度分析

Analyses of Kinematic Accuracy Reliability and Sensitivity for a Planar Linkage Mechanism

针对平面连杆机构传动路线长,存在较大的积累误差,对机构的运动精度产生的影响不容忽视的问题,提出了加工误差、结构变形、装配间隙及铰链磨损多因素耦合作用下运动机构精度可靠性分析的建模方法及求解流程。用动量交换法建立铰链间隙的碰撞模型后对机构进行动力学分析,基于动力学分析结果,利用胡克定律及有限元法分析部件变形,利用Archard磨损模型分析铰链的磨损量。在此基础上,给出了加工误差与部件变形影响下杆长的分布参数以及装配间隙与铰链磨损影响下铰链间隙的分布参数,然后将铰链间隙用无质量连杆模型替换,建立并求解机构的运动方程。通过对飞机舱门收放机构的算例分析,得到了该机构在不同收放次数下的运动精度可靠度及对应的可靠性灵敏度,并给出了制造维护建议,证明了方法的可行性。

Planar linkage mechanisms are widely applied to many machines .But such a long trans-mission distance will cause a large error accumulation ,and the impact on the kinematic accuracy can not be ignored .A modeling method of kinematic accuracy reliability analyses and simulation process was proposed considering multi-factor coupling effects of manufacturing errors ,structure deformation , assembly tolerance and hinge wear .The dynamics analyses of the mechanism were carried out after the clearance joints were dealt with momentum exchange approach .Based on the results of dynamics ana-lyses ,the Hook’s law or finite element method was used to analyze the deformation of the components and Archard’s model was used to analyze the wear depth of each joints .Follow that ,the closed vector position equation of the mechanism was established after the clearance joint was replaced with mass-less link considering manufacturing errors ,structural deformations ,and a kinematical accuracy model-ing method was also proposed considering the multi-factor coupling effects .The feasibility of the pro-posed method was proved by the kinematic accuracy reliability and sensitivity analysis of an aircraft door retractable mechanism and finally gives some valuable advices for manufacture and maintenance process .