Ti. Fossen et Oe. Fjellstad, CASCADED ADAPTIVE-CONTROL OF OCEAN VEHICLES WITH SIGNIFICANT ACTUATORDYNAMICS, Modeling, identification and control, 15(2), 1994, pp. 81-91
This paper presents a cascade adaptive control scheme for marine vehic
les where the non-linear equations of motion include a model of the ac
tuator dynamics. The adaptive controller does not require the paramete
rs of the vehicle dynamics and the actuator time constants to be known
a priori. Both the velocity and position tracking errors are shown to
converge to zero by applying Barbalat's lemma. Global asymptotic stab
ility is proven for the velocity scheme while the position/attitude co
ntroller is only proven to be convergent. Furthermore, all parameter e
stimates are shown to be bounded. Computer simulations of an ROV speed
control system and an autopilot for automatic ship steering are used
to illustrate the design methodology.