Research And Development Of The New Type Multi-degree Of Freedom Controllable Underwater Towed Vehicle

Man is now sparing no effort to explore and research the ocean. The research investmentis increasing. Many kinds of underwater technologies have made great progress. Currently,the underwater towed system is still an effective tool for marine scientific research. Theunderwater towed vehicle is still an effective carrier which equipped with science measuringinstruments in marine environmental surveys, seabed topographic mapping, underwatersearch and military reconnaissance. The main work of this paper is design and develop apractical and controllable underwater towed vehicle which meets the mission requirements.By searching and gathering a lot of research information about the underwater towedsystem as the main object of study, this paper analyzes and summarizes the generalcharacteristics of the underwater towed vehicle and points out the advantages anddisadvantages of existing underwater towed vehicles. In addition, on the basis of previousstudies, through the tank test and the river test, an underwater towed vehicle with features ofexcellent overall performance and better usability has been devised. Work done andpreliminary research results obtained in this paper are mainly the following aspects:1. In the introduction, the paper describes the research history and development status ofunderwater towed systems and emphasizes several major technical aspects in the field ofunderwater towed system research, including hydrodynamic performance studies, depthcontrol and automatic control technology. The paper points out some inadequacies of theexisting underwater towed system designed in this paper, which leads to the development of amulti-degree of freedom controllable underwater towed vehicle.2. We have made two preliminary design proposal. Through comparative analysis wepreferred vertical airfoil program. Two buoys symmetrically arranged above the body, whichwill increase the stability and overall structural strength of the towed vehicle in thispreliminary design. The body has a streamlined shell structure to ensure the stability of course.Using hydrofoil can realize the depth control. Using propeller controller can achievehorizontal movement.3. We comparatively analyzes the lift and drag performance of two kinds of airfoil formof hydrofoil by numerical simulation. Ultimately, we preferred NACA0012airfoil. Using the form of the trailing edge flap can effectively reduce the required thrust. By controlling theflap deflection, it can adjust the lift of the towed vehicle to realize the depth control.4. Through the weight and the center of gravity calculations, the size and material of theconstituent parts of the body have been determined. Adjusting the weight distribution and areasonable set of buoyancy tanks finally keep the center of gravity and center of buoyancy ofthe towed vehicle located on the same vertical line. Besides, the pitch adjustment device isprovided.5. Through pool and river tests, the stability, structural strength, maneuverability andhydrodynamic performance of the underwater towed vehicle prototype are detected. Wepromptly resolved the problems exposed in the test, and also improved the test measurementmethods.Experimental results show that the underwater towed vehicle presented by this designhas a good heading stability, self-stabilizing ability, easy posture control, high manipulationefficiency and simple control mechanism. It has a high practical value.