Control of Autonomous Underwater Vehicles

Abstract

In this thesis an overview of Autonomous Underwater Vehicles (AUV) is presented which covers the advancements in AUV technology in last two decades, different components of AUV and the applications of AUVs. A glimpse on AUV research in India is presented. A nonlinear model of AUV is obtained through kinematics and dynamics equation which is linearized about an operating point to get linearized pitch & depth plane model. A two loop controller (PI control) is used to control the pitch and in turn the depth of the AUV. After having developed, simulated and analyzed the pitch and depth controller for a single AUV, we focus our attention towards developing formation control of three AUVs. The formation control for multiple Autonomous Underwater Vehicles (AUVs) is considered in spatial motions.The objective is to drive a leader AUV along a desired trajectory, and make the follower AUVs keep a desired formation with respect to the leader’s configuration in 3-dimensional spaces (leader-follower formation control). Also, an obstacle avoidance scheme, using pitch and depth control, is used to avoid static obstacles in the path of AUV. The results of the above three control objectives such as tracking control of AUV, controller for avoiding obstacles and formation control of multiple AUVs are presented and discussed in the thesis.