Concept Design of Autonomus Underwater Glider

Underwater gliders are Autonomous Underwater Vehicles propelled by buoyancy change to follow a "Saw-tooth" pattern of motion in sea. They are characterised by long endurance, low speed and low cost. Unlike propeller-driven AUVs, Underwater Gliders use buoyancy for altitude change and wings to produce forward motion. They find applications in areas like underwater surveillance and oceanographic research/survey. Various technologies/methods are presently in use to produce the buoyancy change, which is the primary means of propulsion. This paper aims to review existing gliders and methods of buoyancy control in use, like piston driven buoyancy tanks, hydraulic fluid operated expandable bladders, methods under research like chemical propulsion etc. This paper also enumerates the methods adopted in designing a 1000 m diving underwater glider. The glider, designed in a modular concept where in the buoyancy engine, roll-pitch motion engine and sensors package are divided into modules which can be changed for repair/up gradation purpose.