Self Tuning Mechanism using Input Scaling Factors of PI like Fuzzy Controller for Improved Process Performance
Neha K. Patil, Bhagsen J. Parvat · International journal of advanced research in computer science and electronics engineering · 2013
Design of fuzzy controller includes mainly selection of rule base, membership functions election and scaling factors. In some applications fixed value of scaling factors generates oscillations in process response. In this paper, an algorithm for tuning of scaling factors of fuzzy PI (proportional-integral) controller based on rule base is proposed. The input scaling factors are tuned by updating factors whose values are obtained using rule base with the error and change in error as inputs. The rules are designed for tuning the scaling factors based on the performance measures such as peak overshoot (OV), Rise time (RT) and Integral of square error (ISE). The performance comparison of conventional FLC with self tuned fuzzy controller has been done in terms of several performance measures such as peak overshoot, settling time, rise time and integral square error (ISE). In addition to the responses due to step set-point change, a disturbance is also added in some systems. Simulation results show the effectiveness and robustness of the proposed self tuning mechanism. A simulation analysis of a wide range of processes with and without delay time is carried out and comparison of results shows improvement due to self tuning of fuzzy controller.