飛行感覚を提示するVR (Virtual Reality) システムがこれまで数多く提案されてきた．本研究では，流水プールと水中HMD (Head Mounted Display) を用いて体験者に飛行感覚を提示するシステムを提案するとともに，飛行感覚の提示において，水中という環境の有用性について検討した．まず，我々は水中HMDによる提示映像の速度と流水プールの流速の関係性を確かめる観察実験を行った．次に，水中の体験において流水が有る場合と無い場合，陸上の体験において風がある場合とない場合の4条件で飛行感覚を比較する実験を行った．飛行感覚を構成する要素を浮遊感・速度感・身体的自由度の3つと捉え, これらの観点で被験者の体験を評価した結果，提案手法は被験者に高い飛行感覚を提示できることがわかった．一方で，体験者に多くの身体的負担を課すこともわかった．その後，提案手法を使用した飛行感覚提示システムを実装し，システム上の課題を明らかにした．以上を踏まえ，実装に関する方針を示すとともに水中で飛行感覚を提示する利点と課題を議論する．
Many VR (Virtual Reality) systems have been proposed to present the sensation of flight. In this study, we proposed a system to present the sensation of flight to the user using a jet pool and an underwater HMD (Head Mounted Display), and investigated the usefulness of the underwater environment in presenting the sensation of flight. First, we conducted an observation experiment to confirm the relationship between the speed of the images presented by the underwater HMD and the flow speed of a jet pool. Next, we conducted an experiment to compare the sensation of flight under four conditions: with and without running water in the underwater experience, and with and without wind in the land experience. As a result of evaluating the subject's experience from these perspectives, it was found that the proposed system was able to present a high sense of flight to the user. On the other hand, it was found that the proposed system imposed a lot of physical burden on the user. Then, we implemented a flight sensation presentation system using the proposed method. The policy of the implementation was presented, and the problems of the system were clarified. Based on the above, we discuss the advantages and challenges of presenting the sensation of flight in underwater.
