Bottom-following control of AUVs using multibeam forward-looking sonar

Abstract

We present a novel sensor-based nonlinear control strategy for bottom-following of autonomous underwater vehicles equipped with a multibeam forward-looking imaging sonar, operating under exogenous forces and moments. Our method uses two sonar-based slant range measurements, indicating the shortest and longest distances to the seabed, to calculate the length of the section that is acoustically illuminated. This ensonified line segment is constrained by an invariant reference that depends on the desired altitude above the seabed. A backstepping control approach is developed based on these two scalar references, incorporating integral action to compensate for unknown constant perturbations. While the control design targets constant-slope environments, simulation results show its effectiveness in handling varying-slope profiles.