The hybrid SOF-PID controller for a MIMO nonlinear system

The application of the hybrid self-organizing fuzzy PID (SOF-PID) controller to a multi input multi output (MIMO) nonlinear biped robot is studied in this paper. The self-organizing-fuzzy PID controller was initially studied by H. B. Kazemian but actually his self-organizing-fuzzy PID controller has limits. The supervisory of the self-organizing-fuzzy PID controller can adjust only a kinds of parameters. In his study he has only tuned proportional gain and other parameters, differential and integral, were set by Ziegler-Nichols tuning method. Ziegler-Nichols tuning method is just kind of table based tuning method and there is no guarantee to sure generated parameter's fitness for current system. So in here the hybrid self-organizing-fuzzy PID controller is introduced to tune some kinds of parameters and tested on a multi input multi output biped robot system. In simulation original controller for biped robot system is the PD controller. Proposed self-organizing-fuzzy PID controller of hybrid structure is applied to tune both of proportional and differential gain of PD controller. Simulation results show that the hybrid self-organizing-fuzzy PID controller is better than the conventional self-organizing-fuzzy PID controller to control multi input multi output complex system