Research On Prediction Of Abrasive Belt Wear Of Robot Grinding Based On Acoustic Emission

Titanium alloy has good thermal stability and excellent atmospheric corrosion resistance,coupled with low density properties,so that it is widely used in the manufacture of key components of aerospace vehicle power plant blades.After precision casting,precision forging or machining,the blades need to go through a surface grinding and polishing process to ensure the surface quality and contour accuracy.Robot abrasive belt grinding and polishing processing technology has become one of the popular research directions in the field of aero-engine titanium alloy blade grinding because of its many advantages such as good flexibility,large operating space,and strong scalability.However,due to the difficult processing characteristics of titanium alloys makes the abrasive belt wear extremely serious,which in turn leads to a decline in the surface quality and processing efficiency of the titanium alloy blade.Therefore,this paper establishes an acoustic emissionbased monitoring system of abrasive belt wear status for the robotic abrasive belt grinding of titanium alloy test blocks,and conducts corresponding research on the abrasive belt wear mechanism during the robotic abrasive belt grinding process,including:1)In the acoustic emission signal analysis of robot belt grinding,the data-driven EMD algorithm is selected as the core of the acoustic emission signal analysis method according to the waveform characteristics of the signal,and the EMD algorithm and its existing derivative algorithms are proposed for the shortcomings Improved CCEEMD algorithm.At the same time,a Monte Carlo test was carried out to prove that the average energy and the logarithmic sum of the average period of the inherent modal functions of the background noise in the actual titanium alloy test block robot abrasive belt grinding processing system are zero.A denoising algorithm combining soft and hard acoustic emission signals.2)During the abrasive belt grinding process of the titanium alloy test block robot,aiming at the main wear form of the abrasive belt(abrasive blunt),establish a relationship model between the abrasive wear height of the abrasive belt and the tangential force of the abrasive belt.The stress state of abrasive particles during the abrasive belt wear process is described.Aiming at the main source of acoustic emission for abrasive belt grinding,a theoretical model of acoustic emission signal power and abrasive belt wear height is established based on the energy principle and the above-mentioned abrasive belt wear tangential force model.The model can be used to predict the abrasive belt wear height.3)Through the abrasive belt grinding wear test analysis of the main processing parameters that affect the abrasive belt grinding wear of the titanium alloy test block robot,the wear law of the abrasive belt in the full service cycle under different parameter combinations and the effect of the abrasive belt wear on the processing quality are obtained According to the analysis of the time-frequency characteristics of the acoustic emission signal of abrasive belt grinding based on the test data,it is concluded that the first threeorder inherent modal functions of the acoustic emission signal correspond to the three stages of abrasive cutting(slip,plough,chip formation),and based on this,the abrasive belt wear model was verified.