Research On Real-time Control Of Machining Quality Stability Based On Condition Monitoring

With the arrival of industry 4.0 and the continuous improvement of intelligence processing,manufacturing industry has higher requirements for products,expecting to obtain more satisfactory processing quality in the processing process.In the cutting process,the machining quality is not only affected by the cutting parameters,but also affected by various physical phenomena,such as tool wear,vibration and cutting temperature.Therefore,it is of great significance to control the processing quality in the process of machining to improve the product performance.In this paper,aiming at the problem of quality fluctuation in the process of machining,the factors that cause the instability of machining quality are studied deeply,the monitoring model of machining state is built,and the machining surface quality is controlled in real time according to the change of machining state.The main research contents are as follows:1.This paper studies the factors influencing the surface quality of machining and their internal mechanism,classifies and summarizes the influencing factors,analyzes the modeling method of the surface quality of machining and establishes the corresponding theoretical model,and analyzes the influence of dynamic factors(vibration,cutting force,tool wear and temperature)on the machining quality from the theoretical level,which lays a theoretical foundation for the establishment of monitoring model and prediction model 。2.Study the feature extraction method of cutting force signal and vibration signal,reduce the data dimension by feature extraction and feature selection of cutting force,and then study the influence of vibration on machining surface profile by converting vibration signal to displacement;represent machining status by tool wear,and establish tool monitoring model for the factors affecting the change of machining status.3.In view of the fluctuation of quality in the process of machining,the influence of the change of machining state on the surface quality is studied,and the optimization model of machining parameters is established to control the surface quality.The current machining state is monitored by the established monitoring model of machining state,and the current machining parameters are adjusted according to the monitored state to adapt to the current machining state and achieve the purpose of controlling machining quality.4.Design and carry out a large number of milling experiments of titanium alloy TC18,verify the proposed method,and compare and analyze different modeling methods and optimization methods.