Design And Experiment Of Spindle Rotation Error Measurement System Based On PSD

The spindle is the core component of numerical control machine,and its rotation error is an important factor affecting the machining precision of the machine tool.The measurement of the rotation error is used to evaluate the precision of the spindle of the machine tool,monitor the running state of the spindle,detect and diagnose the failure of the spindle in time,so it has important practical significance.Position Sensitive Detector(PSD)is a kind of position detection device,it has the characteristics of high position resolution,fast response,simple processing circuit and so on,and it's suitable for on-line measurement of position error.Therefore,PSD is applied to the measurement of spindle rotation error in this paper.A rotation error measuring system which is suitable for online measurement is designed and developed,and it is verified by experiments.The main contents of this paper are as follows:(1)The working principle of PSD is analyzed,and a method of edge measurement based on PSD is designed for the online measurement of spindle rotation error.The factors affecting the accuracy of the measurement method are analyzed.The background light compensation algorithm is used to compensate the ambient background light,and a variety of methods are used to correct the nonlinearity of edge measurement based on PSD,the correction accuracy is analyzed.(2)According to the requirements of measurement system,the time domain two point method is used as the error separation method of the measurement system through the comparison and analysis of the simulation.The influence on positioning error for accuracy of the measurement system is analyzed.Use minimum circumscribed circle method to evaluate the rotation error after separation,and the genetic algorithm is used to solve it.(3)The measuring system of spindle rotation error based on PSD is developed.The overall measurement scheme of the measurement system is designed,the system hardware is analyzed and selected,and the hardware platform of the measurement system is set up;Modularized design of each function of the measurement system,the software of rotation error measurement system based on Virtual instrument platform is developed.(4)The rotation error measurement system is tested by experiment.The background light compensation experiment is firstly carried out to verify the effectiveness of the background light compensation algorithm.Neural network method is used to correct the nonlinearity of edge measurement based on PSD,which improves the measurement accuracy of measurement system.Finally,the Contrastive experiment is made with the rotation error measuring system based on the eddy current displacement sensor,the validity of the measurement system designed in this paper is verified.