Human-Centered Automatic Tracking System for Underactuated Hovercraft Based on Adaptive Chattering-Free Full-Order Terminal Sliding Mode Control

Considering the difficult maneuverability of the hovercraft and the driving burden of the pilot, an automatic tracking system including an intuitive human-computer interface and an adaptive chattering-free full-order terminal sliding mode (ACFTSM) controller is designed for humans (non-engineers in particular). The human-computer interface is easy to be understood and used. For the design of the controller, four degrees of freedom (DOF) model of hovercraft is established. And based on the four DOF model, the desired velocities are proposed by a TSM manifold to achieve the finite-time trajectory tracking. Then, the desired velocities can be tracked by the designed CFTSM controller which has superior properties, such as fast and finite-time convergence, highly robust to the disturbances, and low sensitivity to the system parameter variations. Moreover, both the chattering and singularity problems of TSM are resolved by the CFTSM method. By the well combining with radial basis function neural networks in this paper, the new method, named ACFTSM, also has an ability to deal with the strong nonlinearity and uncertainty of hovercraft's complex model. The controller guarantees the fast and finite-time convergence of velocities and position tracking errors. And numerical simulations are implemented to demonstrate the robustness and superiority of the designed controller.