Research On Key Technologies Ofhovering-type AUV

As the need for hovering-type AUVs from the field of ocean engineering and submarine investigation becomes stronger and stronger, it is very meaningful to develop such a kind of AUV, which is highly autonomous and can hover and operate on a precisely assigned point. Under the support of"Research on Key Technologies of Hovering-Type AUV",the self-research program coming from the State Key Laboratory of Ocean Engineering in Shanghai Jiao Tong University, this paper have done some research on the hovering-type AUV testbed"MM-01"and finished the system design and integration. Based on the technology of real-time image processing, we researched on the navigation system based on machine vison. After building the simplified AUV dynamics model,this paper adopted the technology of behavior-based control and designed the high-level autonomous control strategy. Finally, this paper built the whole system model in Matlab Simulink and verified the rightness and validity of the designed control strategy.At first, this paper finished the draft design of AUV's motion control system and navigation system based on machine vision according to the system's function requirement. All sensors and actuators were integrated and low-level hardware motion controller based on industrial card series EPC2900 MiniISA were built, which provides the testbed for the coming design and verifying of control system.Then under the support of image processing software HALCON, the underwater locating experiment based on machine vision was held and the results strongly supports the validity of vision system used for locating in small-scale uncerwater space.For the goal of system simulation, simplified AUV dynamics model was built according to characteristics of AUV in a low speed and finally AUV dynamics state function was obtained. After investigating lots of international papers and books and mastering the bacic principle of behavior-based control and fuzzy control, this paper did the basic research of AUV's high-level autonomous control strategy.Three elementary behaviors of Wandering, Cruising and Obstacle-Avoiding are designed. In Wandering behavior AUV takes large-scale swings with the loss of navigation information; in Cruising behavior AUV performs the predefined trajectory tracking in three-dimension space; in Obstacle-Avoiding behavior AUV avoids the cylinder shape obstacles and continues sailing to predefined target spot. Adopting the coordination mechanism based on priority, AUV can successfully perform the task of moving from start point to final target point by the sequencial coordination of such three behaviors.Finally this paper performed model building and simulation of the whole AUV system including high-level autonomous control module, sensor and environment module and vehicle and motion control mudule.The results showed that the designed control strategy based on behaviors is effective.Afer that this paper developed the AUV monitor and control software based on VB, which was finally used for the water-tank test.