Real-Time Monitoring And Experimental Study On Load Torque Of Machine Tool Spindle

In the actual cutting process,because of the uneven surface allowance,the difference of the material and the wear state of the cutting tools,the cutting parameters and the experience can be adjusted.Because the cutting process is a strong nonlinear and uncertain complex dynamic process,it is affected by the surrounding environment and working conditions.The frequent fluctuation of spindle load will reduce the life of spindle and tool wear,and also restrict the quality and efficiency of parts.At present,the real-time monitoring of cutting force has become a means of machining process monitoring.However,it is generally used in the experimental stage to measure the three-dimensional force directly by the force measuring instrument,which is difficult to meet the needs of the actual project.Therefore,based on the SIEMENS 840 D CNC system,this paper studies the real-time monitoring of machine load based on the open CNC system,and puts forward the control method under the unstable condition.The main contents of this paper are as follows:(1)based on the SIEMENS 840 D CNC system,the hardware and software structure of the system is analyzed.The advantages and disadvantages of three kinds of information acquisition are compared.This paper studies the form of access to the internal variables of the CNC system and the system configuration of the OPC UA(OPC Unified Architecture)server.Under the open CNC system,the overall structure of machine condition monitoring based on OPC UA is proposed.(2)the generation and transmission path of cutting load are analyzed.Two kinds of test schemes are designed to simulate the complex working conditions,and the influence of each factor on the spindle load fluctuation is analyzed by designing a single factor experi ment.Using orthogonal experiment and grey correlation analysis,the weight of the factors and the degree of significance are obtained.(3)through the basic experimental research,the mapping model between the spindle load torque and the working condition parameters is established.A dynamic model based on NARMA-L2 is proposed to predict the variation of spindle load torque.Different control strategies are put forward based on different working conditions,and the feasibility of synchronous operation in spindle load torque control is analyzed based on SIEMENS 840 D CNC system.(4)the machine condition monitoring software is developed based on the C# language,and each module of the monitoring software is designed.The SQL database is used to store and quer y the data.And the machining state and tool condition monitoring are tested.Finally,a set of cutting experiments are designed to analyze the change of spindle load torque.The results show that it is feasible to reduce the fluctuation of spindle load and protect the cutter under the condition of nonsteady load.