Development of Underwater Vehicle for Virtual Mooring

近年来，对地球环境变化的预测和对生态发展的研究变得重要。对于这种研究，在时间和空间上的海洋数据是必需的，并且已经通过系泊系统获得。然而，传统的系泊系统只能观测到垂直空间中的离散数据，而且这种系统的构建需要大量的人力和费用，为了解决这个问题，研究了一种用于虚拟系泊的水下机器人。搭载各种观测设备的潜水器在海面和海底之间来回滑行，收集海洋数据。当潜水器返回海面时，测量数据通过通信卫星传输到研究基地。然后车辆通过GPS自动检查其当前位置。如果由于海流等原因，该位置在虚拟系泊海域之外，控制潜水器，使其在下一次潜水期间返回先前的区域。潜水和浮出水面定期重复。本研究建立了水下航行器（碟形滑翔器）虚拟系泊的数学模型，测量了航行器的水动力系数，并进行了运动仿真和滑行性能水池试验。在此基础上，研制了试验平台车“LUNA”。仿真和在“月球”上的实验结果表明，利用碟形滑翔机进行虚拟系泊是可行的。

In recent years, predictions of changes in the environment on earth and studies on ecodevelopment have become important. For this research on going ocean data in time and space is required, and has been obtainable using by mooring systems. However, a conventional mooring system can observe only discrete data in perpendicular space and moreover, construction of such a system requires a manpower and great expense.To solve this problem, an underwater vehicle for virtual mooring is studied. The vehicle that houses various pieces of observation equipment glides back and forth between the sea surface and the seabed collecting ocean data. When the vehicle returns to the sea surface, the measured data is transmitted to a research base by a communications satellite. The vehicle then automatically checks its current position by GPS. If the position is outside the sea area of virtual mooring because of currents etc., the vehicle is controlled so that it returns the previous area during its next dive. Diving and surfacing are repeated periodically. On the seabed, the vehicle rests for a predetermined period and power other than control equipment is shut off in order to cut down on battery consumption.In this research, the mathematical model of the underwater vehicle (disc-type glider) for virtual mooring was built, and hydrodynamic coefficients of the vehicle were measured, and motion simulations and tank tests on gliding performance were carried out. Then, the testbed vehicle "LUNA" was made based on these results. The simulated and experimented results on "LUNA" showed that virtual mooring by the disk type glider is possible.