Fluctuation Testing Device On Feed System Of CNC Machine Tool

The feed system of CNC machine tools refers to the control and motion unit which completes the feed action according to the instructions of CNC system.It consists of position control unit,speed control unit,servo system,detection and feedback unit and mechanical execution unit.In the process of machine tool operation,because of the unstable input current,structural vibration or inaccurate control algorithm,the actual motor speed and feed speed in the feed system will fluctuate above and below the instruction value,resulting in the fluctuation of the machine tool worktable,which will seriously affect the shape and accuracy of the machine tool parts surface.In order to find out the cause of the fluctuation of the machine tool feed system,this paper develops a numerical control machine tool feed system fluctuation test system.The main research work of this paper includes:(1)This paper analyzes the possible reasons for the fluctuation of the feed system of CNC machine tools and determines the types of internal and external signals of CNC machine tools which need to be collected in the test system,including the internal data of the synchronous servo motor encoder,the tracking error of the feed axis and the external signals of the vibration of each part of the feed system,the servo drive control current and so on.(2)According to the internal and external signals of the machine tool to be tested,this paper determines the software and hardware structure of the fluctuation measurement system for the feed system of the CNC machine tool and confirmes the specific models of vibration acceleration sensor and Hall current sensor and the positions and postures of various sensors on the CNC machine tool.The collectors of vibration signal,current signal and speed signal are described.(3)Introduced the software structure and implementation method of the fluctuation measurement system of CNC machine tool feed system,including the design of each functional module in the software,the communication between the software and CNC machine tool,the specific method of acquiring the external sensor data and the internal sampling data of CNC system,the customization of the testing process and so on.(4)Finally,this paper builds a fluctuation measurement system of CNC machine tool feed system.By adjusting the servo drive parameters of CNC machine tool feed system,the feed system deviates from the normal working state to simulate machine tool failure,which preliminarily verifies the feasibility of the designed experimental system.