The Development Of The Horizontal Machining Center's Remote Fault Diagnosis System

The reliability of the new type machining center which is researched and developed independent is a key factor to influence its performances.It's an important method that analyzing its reliability to improve the performances of the machining center.The remote fault diagnosis of the machining center is an important content of the reliability analysis.In the process of the machining center running,to run safely and stably,avoid the occurrences of major accidents,improve the productivity and the utilization rate of the machine tools,its performances should be improved.In this paper,aiming at the actual situations,the fault diagnosis system based on the rotating parts of the machining center and based on the numerical control system of the machining center is designed and developed.Furthermore,the finite element life of the machining center's turntable is analyzed.The achievement of communication is the basic of solving the problems of remote fault diagnosis.Firstly,the Industrial Ethernet is chosen by the RS-232C interface to achieve the communication between the numierical control system and the communication devices.Using the communication between the 3Gmodem module of telecommunication equipment and the computers,the transmission of data is achieved,the required data is got.The fault data is the basic to make sure if the resulting signal is failure.The designing of the machining center's fault diagnosis system is separated to two parts:the fault diagnosis system based on the rotating parts and based on the numerical control system.The fault diagnosis system based on the rotating parts is based on the vibration signal processing.Fault characteristics are extracted to achieve the goals of fault diagnosis.Firstly,the fault vibration signals are dealt with.The time domain analysis is used,including the statistical feature parameter analysis and the correlation function analysis.The frequency domain analysis is used,including the amplitude spectrum analysis,the power spectrum analysis,the cepstrum analysis and the refinement spectrum.In addition,the wavelet analysis method is introduced to deal with the vibration signals and extract the fault characteristics when the machining center starts and stops,in order to make users diagnose fault easily.The diagnosis system is designed by MATLAB software.By the modal test of the machining center's turntable,the accuracy of the established finite element model is verified.The result of the correlation analysis between the calculated value and the test value of the turntable's natural frequency is got.It can be used to analyze the fatigue of the finite element model later.It's got that the life of the designed turntable achieved the expected design value.The fault diagnosis system based on the numerical control system of the machining center is to diagnose fault according to the alarm provided by fault case library to the numerical control system.There are three parts of contents in establishing the fault case library,including the users machine custom fault information,Siemens 840D fault alarm manual,the analyzed results of the machining center's fault states,causes and hazard,etc.After arranging the machining center's faults,programming software is combined to design the interfaces of human-computer interaction,what s more,the function of the faults' classification statistics is added.There is certain reference value in fault prevention and decision.