World Applied Sciences Journal 15 (3): 422-428, 2011 ISSN 1818-4952 © IDOSI Publications, 2011 Corresponding Author: Payman Ferdosali, Industrial Electrical and Electronic Engineering Sanatkadehe Sabze Pasargad. CO (S.S.P. Co), NO:16 , PO.Code 71347-66773, Fourth floor, Dena Apr, Seven Tir Ave, Shiraz, Iran. 422 Designing On-Line Tunable Gain Fuzzy Sliding Mode Controller Using Sliding Mode Fuzzy Algorithm: Applied to Internal Combustion Engine Farzin Piltan, Nasri Sulaiman, Iraj Asadi Talooki and Payman Ferdosali 1 1 2 2 Department of Electrical and Electronic Engineering, Faculty of Engineering, 1 Universiti Putra Malaysia 43400 Serdang, Selangor, Malaysia Industrial Electrical and Electronic Engineering SanatkadeheSabze Pasargad. CO (S.S.P. Co), 2 NO:16 , PO.Code 71347-66773, Fourth floor , Dena Apr, Seven Tir Ave , Shiraz , Iran Abstract: This paper expands a fuzzy sliding mode based controller which sliding function is on-line tuned by sliding mode fuzzy algorithm. The main goal is to guarantee acceptable trajectories tracking between the internal combustion engine (IC engine) air to fuel ratio and the desired input. The fuzzy controller in proposed fuzzy sliding mode controller is based on Mamdani’s fuzzy inference system (FIS) and it has one input and one output. The input represents the function between sliding function, error and the rate of error. The outputs represent fuel ratio, respectively. The sliding mode fuzzy methodology is on-line tune the sliding function based on self tuning methodology. The performance of the sliding mode fuzzy on-line tune fuzzy sliding mode controller (SFOFSMC) is validated through comparison with previously developed IC engine controller based on sliding mode control theory (SMC). Simulation results signify good performance of fuel ratio in presence of uncertainty and external disturbance. Key words: Internal combustion engine Sliding mode controller Fuzzy sliding mode controller Sliding mode fuzzy on-line tune fuzzy sliding mode controller INTRODUCTION theoretical design of these controllers was valid, at that The internal combustion (IC) engine is designed to designs. Therefore, the production of these designs did produce power from the energy that is contained in its not exist and engine designers did adopt the methods. fuel. More specifically, its fuel contains chemical energy Due to the increased production of the microprocessor in and together with air, this mixture is burned to output the 1990's, it became practical to use these mechanical power. There are various types of fuels which microprocessors in developing more complex control and can be used in IC engines namely; petroleum, diesel, estimation algorithms that could potentially be used in bio-fuels, and hydrogen [1]. Modeling of an entire IC production automotive engines. Specific applications of engine is a very important and complicated process A/F ratio control based on observer measurements in the because engines are nonlinear, multi inputs-multi outputs intake manifold was developed by Benninger in 1991 [5]. (MIMO) and time variant. There have been several engine Another approach was to base the observer on controller designs over the past 40 years in which the goal measurements of exhaust gases measured by the oxygen is to improve the efficiency and exhaust emissions of the sensor and on the throttle position, which was researched automotive engine. A key development in the evolution by Onder [6]. These observer ideas used linear observer was the introduction of a closed loop fuel injection theory. Hedrick also used the measurements of the control algorithm by Rivard in the 1973 [2]. This strategy oxygen sensor to develop a nonlinear, sliding mode was followed by an innovative linear quadratic control approach to control the A/F ratio [7]. All of the previous method in 1980 by Cassidy [3] and an optimal control and control strategies were applied to engines that used only Kalman filtering design by Powers [4]. Although the port fuel injections, where fuel was injected in the intake time it was not realistic to implement such complex