Research On Real-time Measurement Technology Of Spindle Error Of Precision Machining Machine Tool

Spindle is the core components of CNC machine tools,high-speed machining machines and machining centers.Their accuracy directly affects the quality of workpiece machining.Through the measurement of the spindle rotation error,the technician can analyze,predict and compensate the working precision of the machine tool spindle,thereby improving the machining accuracy of the workpiece.Therefore,the measurement of the spindle rotation error is indispensable.The main research contents of this paper are included as follows.1)Design of spindle rotation error measurement schemeIn this paper,the three error types of the spindle,including axial rotation error,radial rotation error and inclination rotation error,are theoretically analyzed.Based on this,a five-channel sensor neasurement scheme is designed.For the characteristics of radial rotation error,Fourier transform and mathematical statistics error separation technique are adopted.The least square circle fitting method is used to calculate the inclination rotation error,and the mathematical statistics error separation technique is used to the axial rotation error.And the above three error algorithm are mathematically modeled.2)Simulation analysis of spindle rotation error measurementBased on the MATLAB software development platform,the spindle rotation error simulation software system is developed.The radial rotation error is simulated and analyzed,and the error separation effect is analyzed according to the result.Based on the Lab VIEW software development platform,a set of experimental software system for simulating spindle rotation error measurement is developed.3)Construction of spindle rotation error real-time measuring deviceHardware measurement systems including air static pressure spindles,NI data acquisition cards and capacitive sensors are built.Software systems including data acquisition,data filtering and data analysis are developed.4)Experimental study on real-time measurement of spindle rotation en'orTaking the laboratory-made aerostatic main shaft as the object,the system verification experiments are carried out with the development of the spindle rotation error real-time measurement system.Repeated experiments are carried out at five different speeds of the spindle to analyze the system repeatability and verify the reliability of the system.The radial ran error obtained by the experiment and the error obtained by the meter measurement method are compared to verify the accuracy of the system.The experimental results of inclination rotation error and axial rotation error are analyzed,and the factors affecting the spindle rotation error are discussed.