Fuzzy logic-based intelligent pid controller for speed control of linear internal combustion engine

Abstract

Internal combustion (IC) engines are widely used in many applications such as automobiles, light aircraft systems, ships/boats, and diesel generators. In order to effectively cater the needs of all these traditional as well as modern applications such as hybrid electric vehicles, the engine speed should be controlled smoothly and rapidly. Usually, proportional-cum integral-cum derivative (PID)-based controller is used for controlling the speed according to the requirement. However, there are some limitations exist with the conventional offline tuning methods available for PID gain parameter design such as restricted to nonlinear changes and poor disturbance rejection due to having constant gain values irrespective of system condition. Besides, the identification of suitable tuning method for a given system is another tedious job. By keeping all these points in view, this paper proposes an intelligent and online tuning method for PID gain parameters using fuzzy logic theory. Instead of tuning the gain parameter values offline, the proposed fuzzy-PID (FPID) tunes the PID gain values online, i.e., the PID gain values are continuously updated according to the system condition. So, this improves the controller ability to reject the disturbances. The system is modeled and simulated using MATLAB/Simulink software. The results proved that the proposed FPID controller provides better transient and steady-state speed response of the IC engine under all conditions.