Adaptive PID Gain Tuning Using Fuzzy Logic and Additional External Performance Index Reference for Controlling Robot Manipulator

This paper addresses an application that involves the control of robot manipulator joint. It tries to explore the potential of using soft computing methodologies in control of plant (robot manipulator) with unknown internal behavior. It presents a PID tuning method that uses a fuzzy logic as a main gain estimator and a signal analyzer, which extract some performance indexes (over shot, rise time and steady state error) from controller error signal. By defining these PI parameters and the one which is available as an external reference, the controller tries to match its output to reach the desired PI. The suggested approach is used to tune the PID gains for different response specifications. Experimental results demonstrate that better performance can be achieved with this EPIR-fuzzy logic (external performance index reference) based PID tuning. Robot manipulator was used as case study in this work and it is simulated with professional simulation software package.