144 Int. J. Convergence Computing, Vol. 2, No. 2, 2016 Copyright © 2016 Inderscience Enterprises Ltd. Adaptive proportional derivative controller using fuzzy logic Ritu Rani De Maity* and Rajani K. Mudi Instrumentation and Electrical Engineering Department, Jadavpur University, Kolkata – 700098, India Email: ritu_maity_8@yahoo.co.in Email: rkmudi@yahoo.com *Corresponding author Abstract: Design of an improved fuzzy rule-based auto-tuning PD controller has been done with conventional Ziegler-Nichols PID controller. It has been observed that for the very common system in industry, the integrating system, the classical Ziegler-Nichols tuned PID controller (ZNPID) gives excessively large value of overshoot and settling time. Here, the proposed controller is a fuzzy auto-tuning PD (FAPD) controller. The value of the derivative gain of the conventional PD controller is continuously updated by a factor α. The value of α is determined depending on the process trend, i.e., normalised value of error (e) and change of error (Δe) and 49 or nine fuzzy if then rules. In FAPD, the updating factor ‘α’ continuously updates the value of derivative gain to provide an overall good performance during set point change and load disturbance. To study the effectiveness of the proposed controller FAPD has been tested and compared with other PID controllers for different integrating systems with varying dead time. Keywords: PID control; PD control; Ziegler-Nichols tuning; auto-tuning; integrating process. Reference to this paper should be made as follows: De Maity, R.R. and Mudi, R.K. (2016) ‘Adaptive proportional derivative controller using fuzzy logic’, Int. J. Convergence Computing, Vol. 2, No. 2, pp.144–160. Biographical notes: Ritu Rani De Maity received her BE in Electronics and Instrumentation Engineering from Vidyasagar University in 2003 and ME in Illumination Engineering from Electrical Department at Jadavpur University in 2006. Currently she is pursuing her PhD in Instrumentation and Electronics Engineering Department at Jadavpur University. Rajani K. Mudi received his BTech and MTech in Applied Physics from the University of Calcutta, India in 1990 and 1992 respectively. Currently he is Professor (HOD) in the Instrumentation and Electronics Engineering Department at Jadavpur University, Calcutta, India and working there since 1992. He was a Guest Lecturer in the Department of Applied Physics from 1993 to 1996 and in the Department of Plastic and Rubber Technology at the University of Calcutta from 1993 to 1995. His research interest includes intelligent instrumentation, fuzzy control and system identification.