FUZZY PID CONTROLLER DESIGN FOR ROBOTIC MANIPULATOR

Abstract

It is well known that a robot manipulator is a highly nonlinear coupled multivariable dynamic system, so that the design of a high performance controller is a very challenging problem which has been tackled by a large number of academic researchers who have proposed various solutions. Convectional PID controllers have been developed and applied for about half a century for many industrial applications. However, it has been known that conventional PID controllers generally do not work well for nonlinear systems, higher order and time-delayed linear systems, and particularly complex and vague systems that have no precise mathematical models. To overcome these difficulties, various types of modified conventional PID controllers such as auto tuning and adaptive PID controllers were developed lately. The present work deals with first design of PD, PID and Fuzzy PID controllers applied to 3-DOF manipulator and later optimal fuzzy PID controller design has been theoretically studied and analyzed. Genetic algorithms are used to tune the Kp, Ki and Kd parameters of Fuzzy PID controller. Here IAE, ISE and ISTE are compared with that of convectional controllers. Simulation results are used to show that the proposed Fuzzy PID Controller produces superior control performance than the conventional PD controllers, particularly in handling complex and nonlinear systems.