Fast Flexible Multi-body Dynamics Analysis And Its Application In Manipulator Optimization

Engineering manipulators are widely used in engineering.The large engineering manipulators currently used generally contain many types of nonlinear links and they are highly complex.With the development of engineering manipulators,in order to improve the working efficiency of the manipulators,high speed has become a key feature of the design of manipulators.In the high-speed working condition,the mechanical arm easily forms a significant inertial force,which causes deformation of the elastic member inside the mechanical arm.If the movement of the beam mechanism reaches the "high speed" area,the moving parts need to be regarded as a "flexible mechanism".If the conventional linear system method is still used for analysis,errors or abnormalities may occur,and even incalculable losses may occur.In addition,considering the possible elastic deformation will significantly increase the complexity of the dynamic model,which is not conducive to solving the problem.At present,many scholars have studied the optimization of engineering manipulators,and proposed different types of solving algorithms.Among them,heuristics are used more,but this method has certain deficiencies,and its efficiency is low.Besides,a large number of simulation calculation processes are required,which limits its application in practice.In summary,this paper focuses on improving the efficiency of optimization.Firstly,the research status of reanalysis and parallel computing at home and abroad are expounded.Secondly,based on its theory,the reanalysis is applied to the computational solution of flexible multi-body dynamics,and parallel calculation is added in the solution process,so that the optimization calculation time is greatly reduced.This study mainly includes two innovations.(1)Introducing the reanalysis method into the flexible multibody dynamics calculation process.As a fast calculation method that can quickly estimate the modified structure based on the initial calculation results,the reanalysis method can significantly reduce the calculation cost and greatly reduce the calculation time.It is very suitable for solving the problem that the multi-body system is complicated and the calculation amount is large..(2)Calculating the use of parallel computing in the solution process.Parallel Computation of Numerical Partial Differential Equations(PDE)The Domain Decomposition Method(DDM)decomposes the computational domain into several subdomains,and the large problem becomes several small problems.The characteristics of reducing the computational scale are very consistent with the characteristics of multi-body systems.Each member can form a natural sub-region with a small common boundary.Finally,in order to verify the effectiveness of the fast solution,the optimization calculation is performed by using the full analysis and the re-analysis method of parallel computation for the same manipulator.The test results show that the fast solution method based on accurate re-analysis can effectively improve the calculation efficiency without reducing the accuracy,and thus has good comprehensive performance.In order to reflect the engineering practicability of the algorithm,the method will be applied to a spatial manipulator motion planning example based on finite element simulation.The optimization results show that the fast solution method based on accurate reanalysis can achieve better comprehensive performance,thus achieving an effective improvement of optimization efficiency.