Design Of Nano Displacement And Positioning Stage Control System On FPGA

With the development of science and technology, Nano positioning technology has been largely used in aerospace, semiconductor industry, biological engineering, medicine and other foremost fields. In the development of many subject areas, Nano displacement and positioning stage is the essential technology. Generally, Nano positioning technology is implemented by Nano displacement and positioning stage. In order to improve its positioning accuracy to Nano-level, research on the control system of Nano displacement and positioning according to the construction of stage modeling and control method, and designs a controller based on FPGA. The main works are as follows:(1)Nano displacement and positioning stage is widely used in some tip area. This thesis states the research significance and development status of Nano displacement and positioning stage and its control system. And it shows the necessity that our country strives to develop the Nano positioning technology.(2)The paper introduces the structure of Nano displacement and positioning stage and its hysteresis, creep and load characteristics, and introduces mechanism analysis modeling, modeling method of system identification and modeling method of their combination. This paper also describes how to use the hysteresis models of piezoelectric ceramic actuator and linear dynamic models of flexure hinge supporting to approximately describe the mathematical model of nanometer displacement and positioning stage. Combining the PI hysteresis model and linear dynamic model, establish a more precise and comprehensive model of Nano displacement and positioning stage by using the combination method of mechanism analysis modeling and system identification modeling.(3) Research on the control methods of Nano displacement and positioning stage system. First of all, introduces the principle and features of open-loop control and closed-loop control in the control methods. Then introduces the principles and parameters tuning methods of traditional PID control algorithm from control algorithms and observes the control effects of traditional PID control algorithm for Nano displacement and positioning stage in MATLAB simulation experiments. Also, explains the principle of self-tuning PID control algorithm and observes its capabilities of parameters identification and controlling in MATLAB simulation experiments. Finally, determine the superiority of self-tuning PID control algorithm comparing the experimental results.(4) In this paper, the development history and trends of programmable logic devices will be introduced, and process and tools of FPGA/CPLD developing will also be shown. Design the modules of error, proportion, integral, and derivative in the Quartus?environment using VHDL programming language, and verifies the effectiveness of every module by simulation experiments.In conclusion, the research of this paper focuses on the control algorithms of Nano displacement and positioning stage. Experiments results shows that self-tuning PID control algorithm is adapted to Nano displacement and positioning stage control system, and its design of controllers on FPGA is available.