Development And Experimental Study Of A Multi-degree-of-freedom Simultaneous Measurement System For The Two-dimensional Stage

In the field of advanced machining and manufacturing,precise stage and precise guide rail are the important moving parts to ensure the manufacturing accuracy of machine tools and the measurement accuracy of instruments.The accurate installation and adjustment of stage and guide rail,as well as the detection and control of their static state and operation condition in geometric space,all require online real-time measurement of multiple degrees of freedom errors.In this paper,the laser interferometer and the autocollimator are unified in the same laser measurement system,in order to achieve multi-degree of freedom simultaneous measurement for a two-dimensional stage.The main job is done as follow:(1)The method of simultaneous measurement of multi-degree-of-freedom is studied in depth.The measurement principle of the laser multi-degree-of-freedom simultaneous measurement system is introduced.The laser measurement optical path is improved based on the integrated optical path layout and polarization interference technology,which improves the stability of the system.(2)In order to obtain the high quality voltage output signal,different signal processing circuits are designed respectively due to the difference of the output optical signals of the displacement measurement optical path and the angle measurement optical path.The circuit board is debugged and made.Thus,the signals with high signal-to-noise ratio are obtained.(3)Under the environment of VC++6.0,the software program of data acquisition and processing system is improved to realize the real-time acquisition,display and storage of measurement datas.(4)Build and debug the multi-degree-of-freedom simultaneous measurement system of two-dimensional stage.Overall performance of the measurement system is tested based on the self-made two-dimensional positioning stage.Such as angle calibration,static drift test,resolution test and comparison experiments,which verify the effectiveness and feasibility of the system.Experimental results show that the system has the resolution of 0.8 nm for displacement measurement and 0.2? for angle measurement.And the system has the range of 50 mm for displacement measurement and the range of ±50? for angle measurement.The position deviation of the multi-degree-of-freedom simultaneous measurement system and Renishaw XL-80 laser interferometer is less than 100 nm within the movement stroke of 50 mm of the positioning stage.In the angle measurement range,The maximum measurement deviations of yaw and pitch of the multi-degree-of-freedom simultaneous measurement system and Renishaw XL-80 laser interferometer are 0.4? and 0.5? respectively.