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.

Research on Optimization Design of Folding Tables and Chairs Group Based on ADAMS

To design a new type of folding tables and chairs group based on the planar linkage mechanism by using a 3D modeling software solidworks and a dynamics analyzing software ADAMS, it is built on four bar mechanism .First ,establish a 3D model of folding tables and chairs group ;Second, simplify the parts of folding; Last but not the least, use the ADAMS to accomplish the optimization design of the group according to the movement characteristics analysis of the corresponding folding parts in the process of expansion and pack up.

The Research on Motion Reliability Simulation of Planar Linkage Mechanism

Taking planar pivot four-bar mechanism for example, the method motion reliability simulation on solving motion reliability of planar linkage mechanism is proposed in this paper. Under the circumstances that manufacturing errors and joint clearances are normal distribution, ADAMS is taken as the analysis platform and the parameterized model of planar linkage mechanism is established by it, then Monte Carlo theory is used to calculate in order that different random simulation model can be obtained. After cycle simulation, the data of simulation will be saved in text files so that it could be used for calculating the result of motion reliability. This method is applied to solving motion reliability of the opening/closing mechanism of the bottom door in the coal hopper, and the result is reasonable, thereby its effectiveness is proved successfully.

Dynamics Automatic Design of Planar Linkage Mechanism Based on Genetic Program

Regarded planar linkage mechanism kinematic target and execution of kinematic pair constraint reaction restrictions as the quantitative objectives, established the comprehensive dynamic design fitness function with the distance between a kinematics target and execution of a set of practical movement points, and the difference between actual constraint reaction of kinematic pair and its limit. According to multi-branch tree expression and random configuration method to create mechanical initial population, driven by the fitness function, made the mechanical population evolution towards the target requirements by the use of copy, crossover and mutation operators of genetic program. In the evolutionary process, inserted kinematics and dynamics automatic analysis technique, design examples indicated that using a genetic program can search parallel in different mechanical configuration space, dimension space and inertia space, automatically searched to such kinds of mechanisms approximate kinematics target and dynamics requirements, thus fulfilling the dynamics automatic design.