Research On A3 Power Head Motion Reliability And Geometric Precision Guarantee Technology

This paper closely combines the reliability and accuracy of the parallel structure spindle head in the engineering application process.Under the support of the National Natural Science Foundation of China and the Tianjin Natural Science Foundation,we will study a parallel two-rotation parallel power head,the A3 head.By studying the limit protection method,the error measurement pose trajectory optimization method and the error identification and compensation method based on principal component analysis,it provides a theoretical basis for ensuring the safe and reliable operation of such equipment and perfecting the geometric precision guarantee system.The main research contents of the full text are as follows:In research of the parallel power head limit protection method,the forward and inverse solution analysis of the mechanism position is taken as the theoretical basis,and the pose judgment simplification algorithm is used as the judgment basis.The system explores the fast,stable and reliable limit protection on the parallel power head.Feasibility,a limit protection method for A3 parallel power head based on the software and hardware conditions of the existing CNC system is proposed.The simulation results show that the method can cover more than 95% of the reachable space of the machine through the combination of software and hardware.It can effectively solve the problem of real-time limit protection of parallel structure machine tools and improve the operation safety of such topological machine tools.In research of error measurement pose trajectory optimization method,based on the geometric error model of the mechanism,a statistical general mapping model between the A3 head end synthesis error and each geometric error source is established.By analyzing the sensitivity,the influence law of various geometric error sources on the digital characteristics of the attitude error of the mechanism is revealed.Based on the idea of optimization problem,an error trajectory optimization model based on sensitivity analysis results is proposed.The model provides an important theoretical basis for optimizing the optimal circular pose trajectory suitable for the measurement of the DBB in the working space of the mechanism.In research of geometric error identification and compensation method,the function mapping relationship between the geometric error source and the end position error is constructed by using the distance error measurement information,and the linear regression model based on distance error is derived.Based on the principal component analysis,the LS-PCA identification algorithm is applied to the parallel power head to change the identification matrix behavior to improve the robustness of the identification algorithm.The residual analysis method is introduced to analyze the robustness of the identification algorithm.The research results of this paper is of important theoretical significance and practical value for improving the operational reliability and safety of A3 parallel power head,enriching and perfecting the geometric precision guarantee system of such equipment.