The Design And Research On The System Of Fine Pointing At Micro Positioning In The Satellite Laser Communication System

Technology of APT is one of the core technology of the communications between relay satellite, it can be fall into three parts:acquisition, pointing, tracking. Our country began to research on the technology of the link between relay s atellite is a little later than those other country abroad. Most of our research is still in the concept of simulation, the basic components and key verification rapidly at present.Fine pointing plays a very important role during the process of pointing an d tracking.The level of fine pointing will be directly influence the stable of the communications between relay satellite and it’s the key point concern the running of the communication. Now these has a large number of both foreign and domestic scholars are trying to study at technology, so the technology of fine pointing at in-depth study is very necessary.Fine pointing at micro positioning system belongs to the high precision and high frequency system, so it need s to have high accuracy and high frequency and response speed. This article is mainly to introduce the fine point ing deflection mirror(is also named FSM), it introduces the fine pointing deflection mirror which is at the core of the micro positioning system, and its role in fine point ingmicro positioning system, and vary on the fine point ing at the micro positioning system in the role of the APT a detailed description. On this basis, the article will introduce the design of the fine pointing at micro positioning system, fine pointing at micro positioning system includes the superior PC, hardware circuit, software program, fine pointing deflection mirrors. The superior PC of the fine point ingat micro positioning system PC is designed by LABVIEW software,for the hardware circuit design,the article emphasis the piezoelectric ceramics driver module and make a detail introduces of the position detection module, the stand or fall of piezoelectric ceramics driver module is directly related to the piezoelectric ceramic can be normal work and fast charge an d discharge, the function of position detection module is detection from piezoelectric ceramic internal resistance strain gauge type of differential feedback back to the bridge circuit consisting of a weak position signal feedback back.Articles will give the fine pointingat the deflection mirror structure, working principle a detailed explanation, then calculate the resonant frequency of piezoelectric ceramic work, it’s prepared for the control next step. For the nonlinear characteristics of piezoelectric such as hysteresis, creep and temperature influence, this paper deals with the hysteresis curve of piezoelectric ceramic mathematical modeling, set up by means of fitting model the hysteresis curve, and forecast through the model of the piezoelectric cerami c as feed-forward control to eliminate the hysteresis error of control system, as well as modeling of creep property. Then in this paper, the fine point ing at micro positioning system control algorithm is described, through comparing the general control al gorithm including the simple closed loop control and PID control, this paper proposes a model based on piezoelectric ceramic predictive feedforward piecewise gearshift integral incremental PID control algorithm. Finally through the establishment of MATLAB simulation and adopt the way of actual product to verify model to verify the effectiveness of the proposed in this paper that based on piezoelectric ceramic model predictive feedforward piecewise gearshift integral incremental PID control algorithm in the control of piezoelectric ceramic brake drive fine point ing at deflecting mirror has the superiority of the other.The technology of fine point is the core of the communications between relay satellite technology, it directly affected the control precision and the bandwidth of a link, fine pointingat the core of the micro positioning system design technology including design the piezoelectric ceramic drive module and position detection module circuit, then the model precision of the mathematical modeling of piezoelectric ceramic actuator is also the main factors influencing the control speed, research on a kind of suitable control algorithm for piezoelectric ceramics driver fine pointingat deflection mirror can effectively improve the control precision.