Model based design and verification of a rapid dive controller for an Autonomous Underwater Vehicle

Abstract

Autonomous Undervvater Vehicles are being considered today by many organizations as a lovv cost substitute for manned vehicles. Requirements forautonomy emphasize the need for a robust system controller that can adequately tnaneuver the vehicle and ensure precise tracking of a planned path. This thesis presents the determination of hydrodynamic coefficients for vertical motion of a radio controlled undervvater vehicle based on open loop testing. The equations of motion vvere manipulated using softvvare Matrix-x to create a satisfactory closed loop control system for rapid maneuvering in the vertical plane. Because vehicle data provided by on-board sensors vvas limited, both state estimation and disturbance estimation/compensation techniques vvere used, leading to a model based compensator vvhich enhanced control. Results shovv that a satisfactory closed loop controldesign can be achieved using these modern controller design techniques. The extension to the design of steering control is addressed.