A Kinematics Velocity Reliability Analyzing Method for Complex Planar Linkage Mechanism Based on Equal-Effective Mechanics Model

The planar linkage mechanism (PLM) is a kind of familiar mechanism. The accuracy of its kinematic parameters, such as displacement or velocity, is crucial to accomplish its function. The parameters are not always precise due to the indeterminacy of some influencing factors. This paper proposes a methodology to analyze the velocity reliability of PLM based on the equal-effective mechanics model (EMM), with the effect of joint clearance, component size randomness and applied force randomness considered. More specifically, how these factors would influence the EMM is studied and then the motion law and risk velocity point of certain part can be obtained. To model the joint clearance exactly, the concept of effective length is recommend. The Response Surface Method (RSM) is used to express the relationship between input parameters and output parameter (velocity), based on which the reliability analysis is conducted. The sensitivities of the parameters are expressed by Sobol variance analyzing method. Finally a certain aircraft cabin door retractable mechanism (one sort of complex planar linkage mechanism) is selected as an example, showing that the approach proposed this article has a great value to be used for engineering object.