Robust Target Interception Strategy for a USV With Experimental Validation

This letter addresses the problem of designing an interception strategy for an underactuated uncrewed surface vessel (USV) in the presence of uncertain external disturbances and unknown internal parameters i.e., linear and nonlinear damping coefficients, vehicle mass, etc. The interception strategy is developed based on the backstepping technique, which guarantees that the relative velocity between the USV and the moving target can globally converge to the desired value. Estimation laws are proposed to estimate the unknown dynamic parameters and external constant disturbances, improving the robustness performance of the interception algorithm. A projection operator is included in the estimation laws which ensures that the estimates remain within a prescribed bound. The stability analysis is provided, and both numerical simulation and experimental results are demonstrated to validate the efficiency of the proposed interception strategy.