Analysis And Optimization Design Of 3-PSS/S Parallel Mechanism For 3C Assembly

3C products is the collective name of computer,communication and consumer electronics,have huge market volume nowadays.As the disappearance of the demographic dividend has led to a sharp increase in labor costs.The number of industrial robots in the 3C industry,which maintains a high growth rate,ranks second only to the automotive industry.However,there are huge differences between the 3C industry and others.3C industry requires for high speed or acceleration,high precision and low-cost at the same time.Currently,commercial robots are flawed inherently in its efficiency and economy when apply to 3C industry,which makes themselves hard to promote in the special application of 3C industry.Aiming at solving problems above,this dissertation makes a further research on the quotient kinematics machine for 3C assembly and develop the corresponding prototype.In this dissertation,a three-rotation-degree parallel mechanism is designed for the orientation adjustment module in the 3C assembly robot.This dissertation first surveyed and screened 3R and 3R-like mechanisms and obtained alternative mechanisms.By analyzing the inverse kinematics,workspace and singularity of the alternative mechanisms,the dissertation compares the results of the collected data and further optimizes the 3-PSS/S mechanism as a sub-module of the quotient kinematics machine for the adjustment of the 3C parts.For the requirements of 3C assembly,the objective function of weighting and maximizing the rotation range in three directions is established,and the constraints are determined according to the characteristics and working environment of 3C assembly.By the MATLAB genetic algorithm toolbox,the dissertation has completed scale optimization design and verified the effectiveness after the comparison.The error analysis of the mechanism is carried out,and the error transfer model of the mechanism is obtained by the vector chain method.The error source which has a great influence on the overall error of the mechanism is obtained,and the processing precision of the corresponding parts is improved.Based on analysis and optimization results,the selection and design of key components such as drive pair,motion sub-chain,passive sub-chain,moving platform and base are completed.And the three-dimensional modeling of the prototype verifies the design rationality.The prototype control system design and hardware selection are completed.The mechanical body and control system are integrated into the control cabinet to develop a complete 3-PSS/S mechanism prototype.And the measurement experiment is completed to obtain the repeatability.The final results meet 3C assembly requirements.