Real time implementation of fractional order PID controllers for a magnetic levitation plant

Fractional calculus has been a topic of great interest for the last few decades. The applications of fractional calculus can be found in the area of viscoelastic and chaotic systems, whose dynamics is expressed in the form of fractional differential equations. The ongoing research work is based on the design of 1-Degree of Freedom (1-DOF) and 2-Degrees of Freedom (2-DOF) Fractional Order PID (FOPID) controllers for a Magnetic levitation (Maglev) plant and the performance has been compared with that of 1-DOF and 2-DOF Integer Order PID (IOPID) controllers in both simulation and real time. The Degree of Freedom (DOF) represents the number of feed-forward control loops in a closed loop system. A 2-DOF controller configuration comprises of a serial compensator and a feed-forward compensator in a closed loop structure. An FOPID controller has a structure similar to that of a conventional IOPID controller, except that its derivative and integral orders are fractional numbers. The design of such a controller requires the determination of five parameters: K_p, K_i, K_d, α and β, where α and β are the derivative and integral orders of the FOPID controller. The controller design problem has been framed as an optimization problem, in which the cost function is formulated from the characteristic equation of the closed loop system at dominant poles that are identified from the given performance specifications. The closed loop response shows that the proposed2-DOF FOPID controller exhibits superior response and robustness with respect to its integer order counterpart.     

基于PID控制的X模式四旋翼飞行器研究

设计了X模式四旋翼飞行器飞行控制系统的总体方案;在此基础上,完成了飞行控制系统的软硬件设计,包括器件选型、硬件电路设计、系统软件设计,并把互补滤波器应用于姿态解算,姿态控制部分采用PID(Proportional Integral Derivative)控制器。通过仿真验证了器互补滤波和PID控制器算法可行性。