Interface Development And Information Processing Of Electro-optical Pod Control System Based On FPGA Platform

This topic is derived from the development of the control system for an optronics pod stabilized platform.Firstly,the hardware design of pod stabilized platform control system is described in detail,and design of the hardware interface of pod control system based on FPGA is explained.Secondly,the research of the gyroscope random error noise identification and filter compensation is carried out,and design and implementation of the gyroscope noise filter compensation algorithm are disserted,in order to solve the problem that low accuracy of the inertial measurement feedback when the low-cost gyroscope is used in pod stabilized platform.The main contents of this paper are shown as below: 1.According to the function of the control system of the pod stabilized platform,design of the control system based on DSP+FPGA is researched and demonstrated,and the top-level scheme of the FPGA interface function design is discussed.2.Design of the finite state machines and asynchronous clock domains in FPGA are used to realize the data read/write timing design of the control system between the pod stabilized platform and peripheral devices,and the exploition of system interface is completed and verified in FPGA.The development process of clock module,UART communication interface module,RDC data collection interface module,DI/DO interface module,XINTF interface module and spare McBSP communication interface module is discussed,and the timing design of each function module is optimized to ensure the real-time reliability of system operation.3.The random error of gyroscope noise signal is researched.The Allan variance analysis method is used to analyze and identify the random error term in gyroscope output signal,and the main random error term is determined.4.The time-series analysis method is applied to establish the random error ARMA model of the gyroscope and Kalman filtering algorithm is employed to compensate the model.It is shown from simulation results that the method has certain ability to suppress the output noise of the low-cost gyroscope.Then,in order to further improve the filtering accuracy of the gyroscope noise signal and the robustness of the filter,an adaptive filter algorithm is used to improve the standard Kalman filter,and the result that the filtering effect of the algorithm is better than the standard Kalman filter is verified by simulation.5.Adaptive Kalman filter is carried out based on FPGA,and the time for the filter to complete one operation is verified by simulation as 30 us,which can meet the real-time requirements of the system.Then,an optical stability platform was set up to verify the adaptive filter algorithm.The filtering results of low-cost gyro are compared with the data of STIM210 gyroscope used by pod stabilized platform.The result that the algorithm can reduce the gyroscope output error noise signal is proved in practical application,which can suppress the influence of noise on the accuracy of the system and approximately achieve the precision of STIM210 gyroscope.