Petrel HUG

Petrel hybrid underwater glider (HUG) is a Chinese autonomous underwater vehicle (AUV)/autonomous underwater glider (AUG)/remotely operated underwater vehicle (ROUV) developed by Tianjin University. After the initial Petrel, a follow-on Petrel II has also been fielded by the same developer.

The need of Petrel HUG is due to the inherent problem of AUG, namely, its speed. Typical speed of traditional AUG is less than 0.5 kt and although at this speed, the endurance of the AUG can last several months, this presents a problem when the speed of the oceanic current is greater than that of the AUG, where it would impossible for the AUG to successfully accomplish its mission. A high speed AUG is therefore needed for prolonged missions in the high speed oceanic currents environment. Petrel AUG is the Chinese answer to this problem. Petrel HUG is designed to combine the advantage of both AUV and AUG, and can act in either role by automatically switching between the two modes based on command or environmental conditions. In addition, there is also a manual override mode to operate Petrel HUG as ROUV via remote control. Petrel HUG is designed by a design team consisting three members of Tianjin University: Professor Wang Shu-Xin (王树新), Associate Professor Wang Yan-Hui, (王延辉, unrelated to Wang Shu-Xin) and PhD graduate student Liu Fang.

Physical attributes
Petrel HUG appears to look like a miniaturized torpedo, with a pair of swept wing at 45 degrees attached to a cylindrical body. The pressure hull contains buoyance and depth control units, and behind them, the mission payload section and centralized control unit. Propulsion system is at the rear section with propellers. Also housed at the rear end of the pressure hull is the antenna duct, which can be replaced by the connector for cables of tether management system. Antenna and wings of Petrel HUG can be rapidly removed for the system to be stored in the container. Petrel HUG adopts modular design concept that allows different payload and propulsion system to be utilized based on customer requests or mission requirement.

Specification for Petrel I:
 * Length (m): 1.8
 * Diameter (m): 0.3
 * Weight (kg): 70
 * Endurance (day): 30
 * Max working depth (m): > 1000
 * Max gliding speed (kt): 0.8
 * Max propelling speed (kt): 3

Specification for Petrel II:
 * Length (m): 2.2
 * Diameter (m): 0.22
 * Wingspan (m): 1.2
 * Max working depth (m): 1500
 * Range (km): 1200
 * Weight (kg); 68
 * Max gliding speed (kt): 0.8
 * Max propelling speed (kt): 3