Modeling and Control of Negative-Buoyancy Tri-Tilt-Rotor Autonomous Underwater Vehicles Based on Immersion and Invariance Methodology

Abstract

Spot hover and high speed capabilities of underwater vehicles are essential for ocean exploring, however, few vehicles have these two features. Moreover, the motion of underwater vehicles is prone to be affected by the unknown hydrodynamics. This paper presents a novel negative-buoyancy autonomous underwater vehicle equipped with tri-tilt-rotor to obtain these two features. A detailed mathematical model is derived, which is then decoupled to altitude and attitude subsystems. For controlling the underwater vehicle, an attitude error model is designed for the attitude subsystem, and an adaptive nonlinear controller is proposed for the attitude error model based on immersion and invariance methodology. To demonstrate the effectiveness of the proposed controller, a three degrees of freedom (DOF) testbed is developed, and the performance of the controller is validated through a real-time experiment.

Special Feature on Advanced Mobile Robotics

“…AUVs (autonomous underwater vehicles) need spot hover and high-speed capabilities to explore an ocean. For this application, Wang et al [27] presented an adaptive nonlinear control to an AUV with tri-tiltrotor. Li et al [28] investigated a particular model of remotely operated vehicles (ROVs) as autonomous underwater vehicles (AUVs), involved with an ocean current model and a cable disturbing force.…”

Disturbance-Rejection Control for the Hover and Transition Modes of a Negative-Buoyancy Quad Tilt-Rotor Autonomous Underwater Vehicle

“…After that, the rotors tilt to 90 • , and the NQTAUV operates in level-cruise mode. Unlike neutral-buoyancy vehicles, the NQTAUV must overcome less drag force [9], resulting in high efficiency and speed.…”

“…The NQTAUV shares the same kinetics equations of the previous version of NTAUV. The kinematics and kinetics equations of NQTAUV are in References [1,9,32] ξ = H(ξ)ω…”

“…Compared with positive and neutral AUVs, negative buoyancy AUVs have the advantages of high energy efficiency, high speed, and a long cruising range. For the development of a previous version of the Negative-buoyancy Tri-tilt-rotor AUV (NTAUV), the attitude-stabilization control system was designed based on Immersion and Invariance (I and I) methodology [8,9]. However, when the NTAUV changes its mode from hover to transition, its asymmetric arrangement of rotors caused disturbance torque to impact the attitude control.…”

Experimental Design of a Mobile Landing Platform to Assist Aerial Surveys in Fluvial Environments

“…Unmanned maritime systems can be divided into two categories: underwater vehicles and surface vehicles [9]. Unmanned underwater vehicles (UUV) [10] are probably the best known and used in robotic applications. The prototype described in this article is an unmanned surface maritime system or USV.…”