Synthetic vision on a head-worn display supporting helicopter offshore operations

Abstract

Helicopters play an important role during both construction and operation of offshore wind farms. During offshore operations, helicopters fly most of the time over open water and often in degraded visual environment. Such scenarios provide very few usable outside visual cues for the crew to safely pilot the aircraft. For instance, hardly any landmarks exist for navigation and orientation is hindered by weather phenomena that reduce visibility and obscure the horizon. To overcome this problem, we are developing an external vision system which uses a non-see-through, head-worn display to show fused sensor and database information about the surroundings. This paper focusses on one aspect of our system: the computer-generated representation of relevant visual cues of the water surface. Our motivation is to develop a synthetic view of the surroundings that is superior to the real out-the-window view. The moving water surface does not provide fixed references for orientation and sometimes even produces wrong motion cues. Thus, we replace it by a more valuable, computer-generated clear view. Since pilots estimate wind direction and speed by checking the movement characteristics of the water surface, our synthetic display also integrates this information. This paper presents several options for a synthetic vision display supporting offshore operations, including texture, grid, and checkerboard symbologies. Further, it comprises results from simulator trials, where helicopter pilots performed final approaches and landings on an offshore platform supported by our display. The results will contribute to the advancement of our HMD-based virtual cockpit concept. Additionally, our findings are relevant to conventional, head-down synthetic vision displays visualizing offshore environments.