The Research And Implementation Of Small Satellite Attitude Simulation With Three-axis Turntable Controlled Via The Internet

Space technology has become an important indication of one nation's scientific and technological development and comprehensive national power; it is also an essential tools and methods of protecting national security. In order to make satellite complete its task quickly and accurately, the research and development of small satellites has boomed in the world since the 1980's."Nanosatellite One", developed and used commonly by the Tsinghua University and Hangtian Tsinghua Satellite Technology Ltd. Co., was launched successfully on April 2004. It is a milestone in the history of China's small satellite research and development.Based on the experience of "Nanosatellite One" successful launch, the issue is proposed by State Key Laboratory of Precision Measurement Technology and Instruments on the purpose of fully simulating the actual flight gesture of small satellites by the control of three-axis turntable via the Internet.(1) The presentation layer provides user-friendly human-computer interactive GUI to the remote user. The paper describes how to use JSF (Java Server Faces) technology with Ajax4jsf SDK to develop the layer.(2) The business logic services layer comprised the Web server and database, the K880 controller card and data collection card component. Based on the mathematical model of three-axis turntable, adopting the PID control strategy as the main control algorithm, we implemented the three-axis turntable controller. The business logic layer received instructions from the application presentation layer, then interpreted and processed them. And then the corresponding instructions were sent to the controller to control the operation of three-axis turntable. The data persistence and business logic in this layer was implemented using the Hibernate and Spring framework.(3) The control execution simulation layer consisted of the stepper motor, its controller and the three-axis turntable; it was in charge of receiving the control instructions and controls the three-axis to carry out simulation motion. The layer collected the motion information of the three-axis turntable though the data collection feedback card and feedback the information to the service layer and application layer, thus forming a closed-loop control structure, constructing a control model with features such as system stability, motion accuracy.Finally, this article summed up the system of the small satellite attitude simulation with three-axis turntable controlled via the Internet, analyzed the weaknesses of the system, and suggested the functions which should be improved and added, and pointed out the direction for the gradual perfection of the system.