Design of fuzzy logic based controller with pole placement for the control of yaw dynamics of an Autonomous underwater vehicle

This paper presents a control strategy using fuzzy logic based approach coupled with classical gain compensator based on pole placement for the analysis of a third order model developed for the yaw plane dynamics of an Autonomous underwater vehicle. However, the first principle based mathematical models formulated for AUV are based on variety of assumptions and uses estimated coefficients to represent the dynamics and uncertain oceanic conditions, may not be the true representation of the actual system. In order to take care of the above unknown disturbances, a fuzzy logic control scheme with state feedback gain compensator based on heuristic knowledge is utilized to compensate model parameter uncertainties. The obvious benefit of the scheme over other conventional methods lies in its simplicity and emulation of common human logic in the design process. It provides good performance objectives such as minimal overshoot, fast rise and settling time and less transient phase oscillations under variety of disturbances encountered in deep-sea environment. The controller formulated is self-adjusting and adaptive in the sense that once it is tuned and customized for a given input domain, it ensures the stable control excursion under variety of operating conditions. Its response and performance are compared with stand-alone fuzzy logic controller and classical state feedback controller designed for yaw dynamics of the system.