Design Of Tracing And Diagnosis System For Mechanical Fault Propagation Of Cnc Lathe

CNC lathes are often used in the machining process.Its status will affect the quality of the workpiece and the efficiency of the workshop.CNC lathe is integrated with computer control and electromechanical system.The logic relation between the internal subsystems is complex,and most subsystems have no intelligent state monitoring function,which makes it difficult to diagnose the faults inside the lathe.Therefore,it is of great significance to analyze the propagation behavior of CNC lathe fault and find a method of tracing the fault propagation of CNC lathe.Firstly,based on the working principle of CNC lathe,the subsystem of the lathe is divided.According to the working process of the lathe,the coupling relationship between the key mechanical parts is analyzed,and the coupling relationship between the mechanical parts is described by introducing the transfer entropy theory;Based on the simulation signal,the rationality of transfer entropy calculation model is verified,and the directed graph of mechanical coupling information propagation of CNC lathe is established.Secondly,the concept of information propagation intensity is introduced to measure the degree of state interaction between mechanical components.The real-time state signals of mechanical parts in the process of NC lathe processing are collected,and the noise reduction and coarse-grained processing are carried out.The net transfer amount of transfer entropy between mechanical coupling parts is calculated by using transfer entropy algorithm,and the information transmission intensity between mechanical coupling parts is measured;Combining the information transmission intensity between mechanical parts with the information transmission phase diagram,the mechanical coupling information transmission network diagram of CNC lathe is constructed.Finally,the sliding window method is used to analyze the change range of the transfer entropy between the mechanical parts of the lathe under different processing modes,so as to determine the probability threshold range of the net transfer amount of the transfer entropy under the normal working state of the lathe;combined with the information transmission network diagram model,a set of CNC lathe fault traceability scheme is formed.Aiming at the tool,which is a special unit with fast degradation,high failure frequency and frequent replacement,the phase change recognition technology is introduced to achieve the purpose of early warning of tool failure.Combined with Matlab GUI platform,a set of CNC lathe condition monitoring and fault diagnosis system is developed.Through the field fault experiment,the accuracy of fault early warning and fault root tracking method is verified by an example.This paper puts forward a fault tracing method for the mechanical coupling fault of CNC lathe,and integrates the method into a simple and fast man-machine interaction system,which can provide strong technical support for the fault diagnosis of lathe in the production process.