Design And Simulation Of Fractional Order Controller For Unstable Systems

The main content of this paper is to use fractional order controller for the compound control and simulation verification, aim at the unstable system as the plant. As the particularity of parameter tuning for fractional order controller. this article adds the fractional order controller after adopting the stabilizing method first, in order to make the system achieve high performance indicators.In order to fully illustrate fractional order controller designs and simulations for unstable systems, three unstable system models are used for the study of the experiment, namely first order unstable system model, first order plus time delay unstable system model and the inverted pendulum system model. For these different system models, three stabilization methods are used. They are for a first-order unstable system using a proportional feedback compensation method to reach steady; for a first order plus time delay unstable system using two proportional integral feedback compensation method to reach stability; for inverted pendulum system using a method of direct introduction of the compensator to reach steady. Based on the three unstable systems, we adopt respectively different stabilization ways. The simulation results show that they reach the intended purpose.Then we have designed fractional order PID controller (PIλDμ controller), fractional order PI controller (PIλ controller), fractional order PD controller (PDμ controller) and integer order PID controller. Finally the simulation experiment shows that the control effect of fractional order PID controller is better than the other controller. For the first-order inverted pendulum system stabilized, we have given the design of fractional order PID controller, fractional order PI controller, fractional order PD controller and integer order PID controller. We also have used the PID controller based on genetic algorithm. And this paper has carried on the simulation experiment. The final results show that the fractional order PID has a better comprehensive performance than the others.