Research On Structure Design And Optimization Of Delta Parallel Robot

With the rapid development of industrial information technology,parallel robots based on Delta mechanism have been widely used in sorting and packing work in the fields of food,electronics and medicine for their high speed,high precision and large bearing capacity,and become a new star in industrial production.This paper takes the Delta parallel robot as the research object,mainly focuses on the mechanical structure design,kinematics analysis,scale synthesis,finite element analysis and structure optimization of the robot.The main research contents are as follows:(1)According to the design requirements of parallel robot,the structural parameters of the robot are preliminary selected.Through the structure of the selected parameters,designed machinery structure and established the model of parallel robot in Solid Works,and completed the choice of calculation of the transmission mechanism.(2)Simplified model of the parallel robot,and the degree of freedom of the mechanism is calculated by the degree of freedom modification formula.The forward and inverse solutions of kinematics were derived by analytic geometry method,and the kinematics example program was programmed in MATLAB.Differential kinematics was used to analyze the kinematics equation of the mechanism,and the velocity Jacobian matrix of the mechanism was obtained.The singularity of the mechanism was obtained by analyzing the Jacobian matrix.The numerical method based on the infinitesimal analysis is used to calculate the volume of the workspace.The forward kinematics solution example is called and the search algorithm is used to solve the workspace by MATLAB,and verify that the workspace meets the requirements.(3)On the basis of the kinematics analysis of the parallel robot,the mathematical model of the optimization problem was established with the maximum workspace utilization as the objective function.The optimal structural parameters were obtained by genetic algorithm and MATLAB software.The optimization results are substituted into the boundary equation of the workspace to verify that the obtained results meet the design requirements.(4)Static analysis and modal analysis are performed on the reconstructed robot model in Workbench.The position of maximum stress and maximum deformation is obtained by statics analysis.Through modal analysis,the position of mode shape and natural frequency are obtained.According to the analysis results,the dangerous position is determined and the improvement measures are put forward.(5)Based on the results of statics analysis,the structure to be optimized was determined.In Workbench,the Deign Explorer module was used to optimize the size of the slave arm and the active arm with variable cross-section,and the Shape Optimization module was used to optimize the material removal of the static platform.Under the condition of satisfying the strength and stiffness,compared with the initial design value,the mass of the slave arm is reduced by 0.1531 kg,the mass of the active arm is reduced by 0.0526 kg,and the mass of the static platform is reduced by 0.7541 kg,so achieve the purpose of lightweight.