Tracking Control of Underactuated Surface Vessels Using Hybrid Control Methods

Tracking Control of Underactuated Surface Vessels Using Hybrid Control Methods Yu Tian Advisor: University of Guelph, 2016 Prof. Simon X. Yang In this thesis, two intelligent control systems are developed for tracking control of an underactuated surface vessel (USV). The studied USV is controlled with uncertain parameters, such as the disturbances from the ocean current. In the first part of this thesis, a new intelligent controller is designed by integrating interval type-2 fuzzy logic control (IT2FLC) with sliding mode control (SMC). Traditional USV trajectory tracking models perform poorly when faced with the dynamic disturbances from wind, wave and airflow. Thus, both kinematic and dynamic USV models are considered in the proposed algorithms. The IT2FLC is utilized to analyze the kinematic model for generating control velocities due to its feature of minimizing the large uncertainties. Then, the IT2FLC is combined with SMC in the dynamic model to generate control law for better tracking performance. In the second part, a hybrid intelligent control system is proposed, which integrates a bioinspired shunting model based backstepping approach and a sliding mode approach. First, the bioinspired backstepping technique is developed to generate virtual velocities based on the kinematic model, which has the capability to resolve the velocity jump problem caused by large initial errors in the conventional backstepping method. Then, the generated smooth velocity signals are used for the dynamic model-based SMC. Furthermore, another bioinspired shunting model is combined with the SMC to provide appropriate control laws for the system to avoid the chattering problem. The effectiveness of the proposed two intelligent controllers is demonstrated through simulation and comparison studies.