Study On Statics And Dynamics Analysis And Optimization Of Parallel Guiding Compliant Mechanism

The development of modern science and technology presents high demands forthe quantify precision, and because of the present market requirement, the balanceshould have high accuracy, high stability and low cost. A type of capacitive electronicbalance was studied in this paper. In this precision measuring instrument, thetransitive accuracy of the parallel guiding compliant mechanism determined theprecision grade of the instrument. In order to improve the character of anti-deviatedload and anti-interference of precision balance, realize its high accuracy and stability,mechanical power component, guiding compliant mechanism was analysed andoptimized. The main research contents are as follows.(1) On the basis of the parallel guiding compliant mechanism, the mechanicmodel was established. Aimed at one compliant beam, by means of the elasticmechanics, this program set up the global stiffness equations of the parallel guidingmechanism’s one compliant beam. Basing on multiple integrals, sectional parametersof the beam element with variable cross-section were obtained by virtue of equivalentmethod, and the finite element analysis software was used to verify the validity of themethod. Therefore, the relation between the dimension parameters and the flexibilityin all the directions were derived.(2) According to the transverse deviated load and the lateral deviated load in theweighing process, bending resistance ratio and torsion resistance ratio of the parallelguiding compliant mechanism were projected, so the relation between the dimensionparameters and the two ratios were derived. Based on the Lagrange equation, thedynamic equation of the compliant mechanism was established, the equivalent massand equivalent stiffness of the compliant mechanism were acquired. Thereby, thenatural frequency of the compliant mechanism was derived. The Matlab software wasused for numerical calculation. The relations between the dimension parameters andthe two ratios, the frequency were draw and analysed, and the impact of somedimension parameters have on the character of anti-deviated load andanti-interference were found out, and the sensitive ranges of the dimension parameterswere acquired.(3) The three performance indexes were turned into the objective functions of themulti-objective optimization. The requirement of the precision measuring instrument’s division value was made to be the constraint condition, and set up thedimension parameters’ boundary conditions. By using the multi-objectiveoptimization software, a Pareto optimal set were obtained. The global optimum waschosen, and the objective function before and after the optimization were compared,and the character of anti-deviated load was testified, and to some extent the characterof anti-interference ability improved.