Research On The Key Control Technology Of Trans-Dimensional 2-DOF Stage System For Nano-positioning

Along with rapid development of science and technology, the requirement of accuracy of measurement has been improved in the field of measurement, only by single driving mode could not realize both high positioning accuracy and large range. The contradiction between large range and high precision is increasingly apparent. So, the development of large range and high precision positioning system has great significance.In order to achieve the target of large range and high percision, this paper developed a macro/micro dual drive 2-DOF stage system with high precision. The system is assembled using large range macro stage and 6-DOF micro stage. The position of each part in the system is identified with machine vision technology and image processing method, sketchy position is realized by driving macro stage moves in high-speed. The 2-DOF stage system’s drive resolution can reach nanometer level by the alternating movement of micro stage and macro stage. The trans-dimensional 2-DOF stage system has advantages of large range, nano-resolution, quick positioning, intelligence, low cost etc.This paper introduces the research work as the following four aspects:1. According to the macro/micro dual drive technology, propose the control scheme of the trans-dimensional 2-DOF stage system. The range of the 2-DOF stage system reaches 200mmx200mm, and the drive resolution reaches nanometer level. The 6-DOF micro stage can compensate the angle error which large movement range and the mechanical structure of macro stage.2. Introduce the design of the trans-dimensional 2-DOF stage system:The system is mainly composed of machine vision module, macro stage module, micro stage module, length measuring module. Length measuring system is composed of probe and laser interferometer. The system adopts the technology of machine vision, machine vision module capturing and recognizing the image. It determines the position of starting point and finishing point. According to the position of starting point and finishing point, set the control parameters and path of macro stage and micro stage.3. Build the control system:To explore the appropriate control method, programming the control software, design the control method of each module, to build a system of closed loop control. In addition, the software adds high speed and low speed convert compensation to improve the efficiency of the system.4. To test the accuracy of each module and the whole system. The results show that the positioning accuracy of trans-dimensional 2-DOF stage system is about 0.3μm. With the correction of error, the positioning error is reduced from 0.3μm to less than 30nm.