An Adaptive Line-of-Sight (ALOS) Guidance Law for Path Following of Aircraft and Marine Craft

This brief presents a novel nonlinear adaptive line-of-sight (ALOS) guidance law for path following, compensating drift forces due to wind, waves, and ocean currents. The ALOS is proven have uniform semiglobal exponential stability (USGES) properties during straight-line following at constant speed. performs similar the classical integral (ILOS) ILOS laws when sideslip angle nearly constant. law, however, has better tracking capabilities rapidly varying caused by time-varying disturbance. because state of additive unknown (disturbance matching). In contrast, must compensate through saturating arctangent function. study also includes an input-to-state stable (ISS) reduced-order extended observer estimation (LOS) crab angle, known as ELOS law. performance ALOS, ILOS, compared simulating rapid changes in stress critical assumptions algorithms. Finally, case Remus 100 autonomous underwater vehicle (AUV) exposed stochastic currents used compare algorithms normal operation.