Research On The Spindle Radial Motion Error Of The Numerical Machine Tools Based On Laser Displacement Sensor

Spindle motion error is a key factor that has great influences on the machining accuracy of the machine tool. Spindle motion accuracy is an important item to evaluate the dynamic performance of the machine tool. Research on the method of detecting spindle's radial motion error of machine tools based on laser displacement sensors is the main content of this paper. First, the development status of detection technology of the spindle's radial motion error both in and abroad China is analyzed. The causes and kinds of spindle's motion errors are particularly analyzed and recognized. Several error measurement and separation technologies are studied. According to the characteristics of the high speed spindle, the three-probe method combined with multi-ring data is developed. Detailed theoretical analysis is discussed; the related measuring method and specific data process technique are given.In order to verify the validity of error separation technique and evaluate its separation accuracy, a specific software system based on Matlab7.0 is developed to simulate the spindle motion error. On this simulation system, the multi-ring three-probe method is applied to simulate the stochastic spindle motion error and the periodic spindle motion error. The results of the simulation show that this method is effective. In addition, the relationship between the number of sampling points and the accuracy of the measurement result is analyzed. At the same time, the paper shows that there is an approximate error in the commonly used equations of the three-probe method.According to the requirement of the multi-ring three-probe method, a hardware system used for high speed spindle radial motion error measurement is built based on CCD laser displacement sensors and a spindle motion error measurement software system based on the virtual instrument technique is developed on LabVIEW8.2.At the end of this paper, the high speed spindle's radial motion error of the XHK-714F machine tool is detected through the radial motion error measurement system. The measurement data is analyzed, the validity of the multi-ring three-probe method is evaluated and the reliability of the measurement system is tested.