Monocular Visual Servo of Unmanned Surface Vehicles with View-field Constraints

In this article, a prescribed performance monocular visual servo (PPMVS) scheme is exclusively created such that an unmanned surface vehicle (USV) can be regulated to reach the desired configuration in the presence of both view-field constraints and unknown image depth. To satisfy view-field constraints, feasible specifications on system outputs are elaborately predefined by virtue of the prescribed performance control technique, and thereby resulting in an equivalent unconstrained visual servo system by incorporating barrier functions. To facilitate stable closed-loop system, the unknown image depth and its reciprocal are respectively accommodated by combining with the backstepping philosophy and Lyapunov synthesis. Completely independent of tuning parameters, the proposed PPMVS scheme makes not only feature points uniformly keep in the image plane, but also the USV asymptotically approach the desired pose. Simulation studies and comparisons on a prototype USV comprehensively demonstrate the effectiveness and superiority of the proposed PPMVS scheme.