Multi-objective Optimization Design Of 3-PRS Parallel Mechanism Based On Isight Platform

The multi-objective optimization of 3-PRS parallel mechanism is designed in this paper based on the designed percutaneous surgical robot. The studied multi-objective optimization emphasis on multi-performance of kinematics and dynamics, the research about how to better optimization algorithms is studied as well. The optimization software Isight is used for the multi-objective optimization of 3-PRS parallel mechanism. The established optimization flow and the evaluation criteria about optimization algorithms presented in this paper have certain reference significance for future research. The main of this paper are as follows:The basic theory of 3-PRS parallel mechanism which is the major part of surgical robot is studied and calculated in detail. Kinematics of parallel mechanism is analyzed,inverse kinematics is calculated. The software Isight and the software ADAMS are combined to simulate and verify the inverse kinematics. Screw Theory and Lie Group Theory are combined to solve the Jacobian matrix. Statics of parallel mechanism is analyzed, equation of static equilibrium is established, force Jacobian matrix is obtained.Optimization objectives of kinematics and statics is studied. These basic researches lay the foundation for the following multi-objective optimization design.Based on the Isight software, the multi-objective optimization of 3-PRS parallel mechanism of surgical robot is designed. The capacities which are established in the paper above are taken as objectives. The NSGA-â…¡ method is used to tackle the multi-objective optimization problem. The well distributed Pareto solution sets and Pareto front are obtained. Objections are studied. The optimization example is given to provide the effectivity of optimization. 6Sigma based robust optimization of 3-PRS parallel mechanism is designed. The kinematics multi-objective optimization is taken as certainty optimization. Firstly, 6Sigma based robust analysis is done, then 6Sigma based robust optimization is done. The analysis for result indicates that the Sigma level and reliability of parallel mechanism experience obviously increase,number of defects per million decreases sharply.Dynamics of 3-PRS parallel mechanism is analyzed. Kinetic equation is established.Kinetic quality matrix is obtained through kinetic energy equivalent principle. Based on quality matrix, kinematic index is established. Fundamental frequency is establishedthrough finite element method. Based on Isight software, The strategy combined DOE sampling method and multi-objective optimization algorithm is utilized to solve the optimization problem. The effect drawing got through DOE experimental design shows the influence extent of every object parameter. The obtained Pareto solution set provides all the feasible solutions. The example given in the end embodies good effect of this multi-objective optimization design,Nowadays, optimization design methods are too miscellaneous to select. For enhancement of optimization quality, this paper presents the method and standard to evaluate optimization algorithms. Based on the NSGA-â…¡algorithm and the NCGA algorithm, the multi-objective optimization of parallel mechanism is studied in this paper. The comparison of optimization quality between these two unnormalized algorithms are made and studied. Experimental analysis indicates that NSGA-â…¡algorithm has obvious advantage on the whole optimization quality.