Global fixed-time position-constrained guidance and adaptive fuzzy prescribed performance control using novel shift function for multiple unmanned surface vehicles formation.

Guidance and control of multiple unmanned surface vehicles (Multi-USVs) present many challenges due to their under-actuation and the unknown environmental disturbance. This research addresses the formation guidance and control problems of multi-USVs by designing a global fixed-time constrained guidance and control formation approach. First, a global fixed-time control Lyapunov function (GFCLF) is proposed using an innovative shift function to deal with the fixed-time output partial constraint.

Design and Analyze a New Measuring Lift Device for Fin Stabilizers Using Stiffness Matrix of Euler-Bernoulli Beam.

Fin-angle feedback control is usually used in conventional fin stabilizers, and its actual anti-rolling effect is difficult to reach theoretical design requirements. Primarily, lift of control torque is a theoretical value calculated by static hydrodynamic characteristics of fin. However, hydrodynamic characteristics of fin are dynamic while fin is moving in waves.