Research And Implementation Of Key Technologies For Health Monitoring Of CNC Machine Tool

With the development of modern big-scale industry,CNC equipment is becoming more and more complex,and the degree of automation is higher and higher.The loss caused by the failure is huge,and the maintenance ability of the enterprise is limited.It is urgent to establish the monitoring and evaluation system for the health state of the numerical control equipment to prevent and diagnose the equipment fault in time and accurately.The health monitoring and evaluation of CNC machine tool is used to evaluate the accuracy of CNC machine tool,and to provide a basis for the high precision manufacturing performance of data machine tool.At the same time,the fault diagnosis and prognosis mechanism of CNC machine tool are realized by combining big data and artificial intelligence technology.The thorough and systematic study of the monitoring system of CNC machine tool has been provided.It includes the theoretical reasoning and guidance of error modeling and error compensation.The multi source fusion technology,the fault diagnosis and early warning of the key parts of CNC machine tool based on big data technology,has a good theoretical and practical significance for the health monitoring and evaluation of CNC machine tool.The main research results are as follows:Research on the standardized monitoring system for the health condition of CNC machine tool has been carried out.It includes: the comprehensive geometry of the high grade CNC machine tool with arbitrary structure is established by using the theory of multi rigid body kinematics.The multi rigid body kinematical model of error is used to study the geometric error transformation matrix of arbitrary structure machine tool by using the homogeneous transformation matrix and its differential.The high precision and fast detection method of the error item of the five axis linkage CNC machine tool is summarized,and the error separation method of the original error item has been put forward.The compensation model for the key error of CNC machine tool is set up,and the compensation model of the key error is established,such as the compensation of the backlash and pitch error and the error compensation model of the over quadrant.The key technologies of CNC machine tool fault diagnosis and prognosis are studied,such as multi source fusion technology based on D-S theory,fault diagnosis and prognosis of key parts of machine tool based on big data technology.The main innovations of this subject as follows:The comprehensive evaluation method for the health condition of CNC machine tool has been proposed,which improves the comprehensiveness of machine tool health assessment.The method not only includes the accuracy detection of CNC machine tool based on the error theory,but also the fault diagnosis and prognosis based on the big data technology.It combines the static precision test and the dynamic test,and combines the current state and historical state,so as to ensure the accuracy and reliability of the evaluation results.The comprehensive error analysis model of the five axes CNC machine tool is set up with the kinematical principle of the five axes CNC machine tool,and the error transfer function is deduced according to the measuring principle of the ball bar instrument,and the corresponding relation between the error and the measuring curve is determined.The separation of the 21 errors items of the machine tool is realized using the laser interferometer and other instruments,combined with the nine line method,improving the efficient of error detection.The basic data are provided for the error compensationThe reverse error compensation algorithm based on speed clamp is proposed to reduce the vibration of the machine tool and improve the cutting quality,and double fuzzy algorithm with a variable parameter has been proposed to control the error of the quadrant by compensating the static friction force.The multi-source data fusion method based on D-S evidence theory is studied.The fault diagnosis and prognosis model of rolling bearing is studied,and the fault diagnosis algorithm and adaptive ARMA fault warning algorithm are proposed and implemented,which is on the premise of ensuring the accuracy.It improves the calculation efficiency of rolling bearing fault diagnosis and prognosis.Finally,the compensation effect of the two-way pitch,the reverse gap and the roundness error is tested on the turning center and the five axis machining center in our institute,and the feasibility of the compensation model and strategy has been verified.