TORI AUV-1 constructed by Mrs. Edward Chen, Sheng-Wei Huang,Cyuan-Si Shi, Shi-Hwa Huang, and Miss Shuei-Junn Chao won the Second Prize in IEEE/MTS OTO'08 Aqua Robot Competition.

OTO08 Aqua Robot Competition will be held on 2008/4/10 in Kobe

Abstract of Mr. Tung, Shui-Min's Master Thesis (2008.02)
This work investigates a design methodology for underwater gliders with fore and aft buoyancy engines. The advantages of using a glider for ocean observations are that gliders have low energy cost for long endurance. A buoyancy engine is a device which changes buoyancy of an underwater vehicle by attracting and expelling water. Underwater gliders equipped with buoyancy engines can be driven by net buoyancy forces. The buoyancy engines??arrangement considered in this study contains two tanks located at the fore and end aft part of the hull. Buoyancy engines considered here are those of piston-type. Forces equations which model buoyancy, gravity, and hydrodynamic forces in gliding are derived. Performances of different sizes of buoyancy engines are compared. Energy for driving a glider with fore and aft buoyancy engines could be estimated by total volume change of buoyancy engines and the cost for holding piston position during transferring. The net buoyancy and position of the center of gravity can be tuned at mean time using the fore and aft buoyancy engines. Operational constrains for gliders using fore and aft buoyancy engines are specified. Following these constrains, energy cost for glider motion will be lower than conventional glider design using single buoyancy and a weight shifting device. This study describes a design methodology for specifying volume capacity of buoyancy engines. Glide angles and glide speeds for optimal energy cost are also specified base on the minimal energy cost. Gliders with rectangular wings of various shape and wing location are then examined in terms of the energy cost for gliding controlled by buoyancy engines.
Keywords: underwater gliders, buoyancy engines, buoyancy driven, underwater vehicles, ocean observation.

Abstract of the Mr. Shieh, Cha-Jin's Master Thesis (2008.2)
Animals improve their energy efficiency and adapt to changes in task requirements or in environmental conditions by controlling joint compliance dynamically. This work mimics fish's propulsion using a compliant tail fin to show the power reduction while the fish propels by the tail fin. A compliance control scheme of caudal joint for a biomimetic autonomous underwater vehicle (BAUV) is presented. The scheme is based on actuators arranged antagonistically about joints. Design considerations on the hardware are presented to reduce the power consumption from actuators and emulate the underlying mechanics fish use to produce movement. Oscillation motions of the tail fin are driven by motors through springs. A state space model and a way-point tracking controller for the BAUV system are presented. A method is derived to determine the optimal spring compliance. Simulations are performed to verify the existence of the optimal joint compliance. Water tank experiments using a BAUV demonstrate that tuning joint compliances can reduce the amount of energy required for the propulsion of the tail fin.
Keywords: biomimetic, underwater vehicles, compliance control, propulsion, energy saving