Study On Angle Measuring And Drive & Control System Of Turret Based On FPGA

The application of turret systems now is more and more extensive, in the space industry, weapons industry and automation and control industry. Along with the development of related technologies, on the turret system, requirements have become more sophisticated, high precision, fast response and so on are required. the turret system should can fast track the target, arrive at the designated location, and also can achieve precise positioning, speed tracking and servo functionality. The turret system design project is the background of the thesis, a double-channel angle measuring system and a drive & control system have been constructed. Both the two system, especially the former, have been researched and analyzed detailedly.Firstly, the angle measuring system is researched. To improve the precision of the angle measuring system and the whole turret system, a double-channel angle measuring system is selected. The principle of the double-channel resovler and the double-channel angle measuring system are given. Then the main parts of the angle measuring system, excitation power, RDC, coupling of the two channels, are designed. To improve the precision as much as possible, the probable errors are analyzed, and the method of error compensation is proposed.Secondly, for the certain deficiencies in the angle measuring system which uses special RDC chip, digital RDC is construced using FPGA, and then an angle measuring system based on digital RDC is constituted. After that the algorithm of the digital RDC, which is the most important part of the system, is analyzed. Three algorithms are researched respectively. They separately are based on the improved CORDIC algorithm, the PLL and the Luenberger Observer. Through comparative analysis of the three algorithms, we get the different characters and the applicable occasions of them. Using MATLAB's Simulink tool to establish PMSM system simulation model based digital RDC, and the simulation results prove the correctness of the three algorithms.Thirdly, the FPGA-based drive & control system of PMSM using in the turret system is analyzed. Math of PMSM is given and vector control scheme of PMSM is mainly researched.At last, the hardware platforms of the double-channel angle measuring system and the drive & control system are constructed. Circuits of excitation power, PMSM drive, PMSM control are designed. Then, in Verilog-HDL Language, main modules of the system such as trigonometric calculations, PID controller, coordinate transformation, SVPWM and so on are developed, and then verified by simulation or experiment. At last, the research of the thesis is verified by relational experimental results.