Trajectory Tracking Control of an Underactuated Autonomous Surface Craft in the Presence of Environmental Disturbances

To achieve a fully autonomous navigation for unmanned surface vessels (USVs), a robust control capability is essential. The control of USVs in complex maritime environments is rather challenging as numerous system uncertainties and environmental influences affect the control performance. This paper therefore investigates the trajectory tracking control problem for USVs with motion constraints and environmental disturbances. Two different controllers are proposed to achieve the task. The first approach is mainly based on the backstepping technique augmented by a virtual system to compensate for the disturbance and an auxiliary system to bound the input in the saturation limit. The second control scheme is mainly based on the normalisation technique, with which the bound of the input can be limited in the constraints by tuning the control parameters. The stability of the two control schemes is demonstrated by the Lyapunov theory. Finally, simulations are conducted to verify the effectiveness of the proposed controllers. The introduced solutions enable USVs to follow complex trajectories in an adverse environment with varying ocean currents.

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Robust trajectory tracking control of underactuated unmanned surface vehicles with exponential stability: theory and experimental validation

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-07-2021-0162 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Rui Yu ◽

Hua Zhou

Keyword(s):

Exponential Stability ◽

Trajectory Tracking ◽

Tracking Control ◽

Control Algorithm ◽

Superior Performance ◽

Parametric Uncertainties ◽

Trajectory Tracking Control ◽

Environmental Disturbances ◽

Content Type ◽

Unmanned Surface Vehicles

Purpose Trajectory tracking is an important issue to underactuated unmanned surface vehicles (USVs). However, parametric uncertainties and environmental disturbances bring great challenges to the precise trajectory tracking control of USVs. This paper aims to propose a robust trajectory tracking control algorithm with exponential stability for underactuated USVs with parametric uncertainties and unknown environmental disturbances. Design/methodology/approach In this method, the backstepping method and sliding mode control method are combined to ensure that the underactuated USV can track and maintain the desired trajectory. In addition, a modified switching-gain adaptation algorithm is adopted to enhance the robustness and reduce chattering. Besides, the global exponential stability of the closed-loop system is proved by Lyapunov’s direct method. Findings The proposed method in this paper offers a robust trajectory tracking solution to underactuated USVs and it is verified by simulations and experiments. Compared with the traditional proportion-integral-derivative method and several state-of-the-art algorithms, the proposed method has superior performance in simulation and experimental results. Originality/value This paper proposes a robust trajectory tracking control algorithm with exponential stability for underactuated USVs. The proposed method achieves exponential stability with better robustness and transient performance.

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