The Design Of Filter For Nano Positioning Platform Controller Based On FPGA

Nano positioning technology is a key technology in the fields of frontier science and engineering technology. Nano positioning technology is usually to be achieved with the form of nano-positioning stage control system. For the nano positioning platform control system, due to the presence of the signal acquisition and quantization noise, mechanical noise of the system affect the positioning accuracy of nano meter displacement platform directly. The noise signal of nano platform affects the positioning accuracy of the platform. The digital filtering algorith is designed to simulate and study in order to solve the question. The main work as follows:(1) The designing significance of filter for the nano positioning platform controller is introduced. The development of nano positioning platform controllers and digital filter are introduced, which show that the filter design of nano positioning stage controller is still in initial stage.(2) In this paper, the presence of noise characteristics in nano positioning stage is analysed,then we can find that the noise is random noise. Because of the common frequency selective filter can not be used to filter out the noise, so we need to adopt Kalman filter to filter out the noise. Thereby the concept of Kalman filter is introduced and the signal model of Kalman filter algorithm is established, and the derivation of Kalman filter algorithm is described in detail.(3) The overall composition structure of nano positioning platform control system is described in this article. The system of nano positioning platform is analysed to establish the model of nano displacement positioning platform. Kalman filter algorithm is used to filter and simulate for nano displacement platform. The amplitude of process noise and observation noise are changed to observe its influence on random noise and the filtering effect of Kalman filter.Experimental results show that Kalman filtering can reduce the positioning deviation of nano displacement platform, which is less then 7nm, and the positioning accuracy can be improved significantly.(4) The ordinary FPGA chip is introduced and its working principle and composition structure are elaborated. The characteristics and function of FPGA chip used in the nano positioning controller platform are introduced. The development tools and FPGA development processes and guidelines are described in detail, and can provide a good foundation for the the development of FPGA.(5) The effectiveness and feasibility of the Kalman filter algorithm are verified based on FPGA in the nano positioning platform control system. The DSPBuilder tool in the MATLAB/Simulink and QuartusII tool are used to achieve the filter design of nano displacement positioning platform controller and simulate. According to the actual response curves show that filtering algorithm can effectively filter out noise generated by the control system in this paper,and verify the feasibility of Kalman filtering algorithm.In summary, this paper focuses on studying the filter algorithm of nano positioning platform controller. Experimental results show the proposed algorithm is feasible, and the positioning accuracy of the system is ensured effectively. The kalman filter of nano positioning platformcontroller is proposed, which has a certain value for designing the reference filter algorithm.