Study On Multi-objective Optimization Design For Parallel Kinematic Machine Based On Isight

Parallel kinematic machine (PKM) is the manufacturing cell consisted ofmanipulators, machine tool, etc. with the parallel mechanism as active feedingmechanism. To establish a platform for the multi-objective optimization design androbust optimization design of parallel kinematic machine based on Isight with thesynthetical consideration about kinematic and dynamic performances, the next aspectswere carried out:(1) The foundation of mathematics of the parallel mechanism was introduced.This part includes the theory of inverse kinematics, Jacobian matrix, dynamic model,mass matrix of operating space and the generalized inertia ellipsoid. The establishmentmethod of workspace, kinematic dexterity, dynamic dexterity, load-bearing capacity,stiffness and actuating force were introduced also.(2) The method and design flow of multi-objective optimization and robustoptimization for parallel kinematic machine based on Isight was established. Theoptimization design flow was built in Isight based on the operating principle of Isightby integrating engineering software. Furthermore, the optimization design platformwas established based on the flow built before.(3) Study cases of multi-objective optimization design for parallel kinematicmachine. The optimization design cases of3-UPS-S parallel mechanism and parallelfine-tuning manipulator4-SPS-S for segment assembly robots in shield tunnelingmachines were carried out. The basic procedure was established by integratingMATLAB, Pro/E, ANSYS and ADAMS to accomplish the modeling, simulation andcalculation of the performance indexes automatically. The influence to the responsefrom factors was achieved by design of experiments. The multi-objective optimizationdesign was carried out based on the quasi-optimal solution achieved from design ofexperiments. The optimization design platform was built by combining the design ofexperiments and optimization design component based on the Task Plan component,and the multi-objective optimization was accomplished. The Pareto set and Paretofrontier were achieved, from which we can select suitable optimal solution eclectically.The kinematic and dynamic dexterity were collectively known as operating dexterity in this paper, and optimization was executed with the objective of the operating dexterity.The local and global operating dexterity were compared between the mechanismbefore and after the optimization. The optimum region of the optimum manipulatorwas defined and calculated.(4) The robust design and optimization case of parallel kinematic machine. Withthe research object of parallel mechanism for pose adjustment of solar collection plate,robust analysis was carried out based on Isight. Furthermore, Six Sigma based robustoptimization with the basis of certainty optimization was executed with the constraintof Sigma level of the random variable and quality constraint, and with the objective ofmean value and variance of the certainty optimization’s objective. The result of therobust design and optimization was analyzed at last.A new method of optimization design for parallel kinematic machine wasproposed. The result indicates that this method is suitable for the optimization designand robust design for the parallel kinematic machine because of its high automaticity,fine visuality, simple operation, high efficiency and reliability.