A Quasi-Velocity-Based Tracking Controller for a Class of Underactuated Marine Vehicles

Abstract

This paper investigates the trajectory tracking control problem for underactuated underwater vehicles, for which a model is expressed in terms of quasi-velocities arising from the inertia matrix decomposition. The control approach takes into account non-modeled dynamics and external disturbances and is suitable for symmetric vehicles. It is shown that such systems can be diagonalized using inertial quasi-velocities (IQVs). The strategy consists of the velocity controller and two adaptive integral sliding mode control algorithms. The proposed approach, introducing velocity transformation and using backstepping methods and integral sliding mode control, allows trajectory tracking for vehicles in described models with symmetric inertia matrix. Proof of the stability of the closed system was carried out using IQV. The proposed scheme has been verified on two 3 DOF models of underwater vehicles with thruster limitations. A brief discussion of the results is also given.

A General Stable Control Method for R-Type Underactuated Robot with Three Different Initial Situations

“…When a joint of the robot is damaged, the actuated robot becomes an underactuated system. Underactuated systems are one typical kind of nonlinear systems, whose number of the control inputs is less than the degrees of freedom of the system motion space [5][6][7]. Such systems are widespread in daily life and include crane [8,9], quadrotor [10,11], helicopter [12,13], unmanned ship [14,15], soft robot [16,17], and underactuated robot [18,19], among others.…”