Optimization And Test Of A Multi-degree-of-freedom Simultaneous Measurement System For The Two-dimensional Stage

With the rapid development of technology and the urgent needs of industrial production,the ultra-precise measurement and manufacturing technologies have played an increasingly important role in the development of modern high-tech industries.As important moving parts in many processing and application fields,high-precision positioning stages and high-precision guide rails provide a prerequisite guarantee for instrument measurement accuracy and machine tool processing accuracy.However,the positioning stage is susceptible to the accuracy of the design process and assembly process.It will generate the angle error of three-degrees-of-freedom: yaw angle,pitch angle,roll angle and three-dimensional positioning error in X,Y and Z directions.In order to further improve the accuracy of the stage,the accurate measurement of multi-degree-of-freedom geometric error is an urgent need for breakthroughs in the development of precision manufacturing.Therefore,in our article,we integrates the two-dimensional stage and the multi-degree-of-freedom laser measurement system together.In order to optimize the stage control system,we use programming software to redevelop and optimize the control system of stage.The error terms in the stage system is analyzed during the research process to improve measurement and compensation accuracy.This thesis specifically completes the following tasks:(1)The stage system with multi-parameter real-time measurement compensation function is established by integrating the computer,the two-dimensional multi-degree-of-freedom laser measurement system and the two-dimensional nano-positioning stage with an angle correction function together.(2)In order to improve the performance of motion control,The VC++ is used to write the stage control program and implement the simultaneous movement of the stage in the X and Y directions.(3)The filtering technology is used during the movement of the stage and effectively reduce the random errors.The control programs,implement the simultaneous movement of the two-dimensional stage and compensate the six degrees of freedom errors are integrated.It improves angle length parameter measurement and compensation accuracy of the stage during the travel of the stage.(4)The factors that affect the accuracy of angle measurement are studied in the thesis.A mathematical model is established to analyze the defocus error caused by the four-quadrant detector deviating from the focal length.A method is designed successfully to compensate defocus error and improve angle measurement accuracy.Experimental results show that the stage can realize simultaneous macro and micro control in X and Y directions.After eliminating the out-of-focus error,the program can realize the simultaneous compensation of six degrees of freedom errors within the movement range of 50 mm × 50 mm.The angle error of two-dimensional stage can be controlled within 1.0? after the angle compensation,the linear positioning error measured by the two-dimensional stage is less than 250 nm.