| Hybrid underwater gliders(HUGs) are a new type of unmanned underwater vehicles(UUVs). They combine the behaviors of traditional autonomous underwater gliders(AUGs) and those of autonomous underwater vehicles(AUVs), and can perform various oceanographic monitoring missions. They have two working modes, buoyancy driven gliding and propeller driven level-flight. In the gliding mode, HUGs dive along a saw-tooth trajectory by means of an active buoyancy regulating unit and an attitude regulating unit. The flight is characterized by high efficiency, long endurance, long range, and low noise. While in the level-flight mode, HUGs can autonomously cruise with high speed and excellent positioning accuracy.This dissertation presents design and development of an engineering prototype of HUG(Petrel-II). With the support of national science and technology projects, Petrel-II is designed to meet the demand of far offshore environmental monitoring. In this dissertation, the general design and unit design of Petrel-II are described. The dynamic model of Petrel-II is also established. Motion analysis according to the dynamic model is conducted under conditions of certainty and uncertainty using numerical simulation. The ranges of main performance parameters are also calculated in the dissertation. The experimental results show a good agreement with the simulation results, verifying the design method and effectiveness of the dynamic model. The main contributions of this thesis are summarized as follows:A novel design method for HUG is presented in the dissertation. According to the design method, an engineering prototype of the first large depth rating HUG in China has been developed. Its depth rating is deeper than 1500 m. Its gliding speed reaches 0.5 m/s and the cruise speed is up to 1.5 m/s in the propeller driven level-flight mode. It can also position and communicate in a global scale.A dynamic model of Petrel-II is established utilizing linear momentum and angular momentum equations, considering the simultaneous effects of the buoyancy unit, the propeller unit, the translation mass, the eccentric rotating mass, and the translation mass, and simplification of the hydrodynamic force. The model can exactly show the motion behaviors of Petrel-II.Based on the dynamic model, the planar motion equations and expressions of the performance parameters in both the vertical plane and the horizontal plane are derived in the dissertation. The relationship between the design parameters and the performance parameters is analyzed according to the equations. Ranges of the main performance parameters in the steady planar motion pattern are investigated by numerical simulation. Moreover, the optimization of key performance parameters in the two working modes is conducted. In this dissertation, scheme and regulations of a new performance test are proposed according to the development process and behavior characteristics of Petrel-II. The documents provide an important direction for function verification and performance evaluation of the vehicle. They can also be used for other similar oceanographic monitoring devices.The uncertainties that exist in engineering practice are considered in the dynamic model of Petrel-II in this dissertation. The uncertain parameters in the dynamic model are classified according to their properties. The dynamic model with uncertainties is established utilizing linear momentum, angular momentum equations, and statistics method. Based on the model, the influence of the uncertain parameters on vehicle performance in the two working modes is analyzed by Monte Carlo Method. The work provides guidance for improvement of system design for Petrel-II. |
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