Integral Backstepping Control for Stabilizing an Underactuated X4-AUV

Autonomous Underwater vehicles (AUV) is one of an unmanned underwater vehicle (UUV) that work independently
and can be control automatically on board without requiring a cable. The autonomous capability has great important
tasks due to navigate in abyss zones and dangerous underwater mission. However, in order to stabilize the system
consists of four control inputs and six degree of freedoms (DOFs) is difficult tasks because of the nonlinear dynamic
and model uncertainties. This paper presents the stabilization of underactuated X4-AUV using nonlinear control
techniques, integral backstepping. The key idea of integral backstepping is to design a virtual controller for each
subsystem by associate with integral of tracking error. The effectiveness of the proposed control technique
demonstrates by simulation.