Advancements in Flight Simulation Visual Systems: An In-Depth Analysis of Variable Collimation Display Technology

Current full flight helicopter simulators typically employ wide-angle collimated (WAC) display technology to provide an immersive and realistic visual experience at far image distances of approximately > 9.1 m (30 ft). While WAC displays are sufficient for many flight tasks, they are limited by their inability to provide correct binocular depth cues at image distances or altitudes approximately < 9.1 m. Such lack of accurate depth cues at close range to ground can impair pilot training and lead to negative transfer of training. This paper reviews the development and testing of Holochip’s Variable Collimation Display (VCD), a simulator display system that provides continuously and dynamically controllable vergence and accommodation binocular depth cues at image distances ranging from 3 m (10 ft) to > 9.1 m (30 ft). A prototype VCD was integrated in the downlook window of a CH-47 transportable flight proficiency simulator (TFPS) and evaluated by U.S. Navy test pilots. Test environments included multiple simulated landing scenarios and target altitudes over a range of 0 to 18.3 m (60 ft). It was found that the pilot’s judgement of distances in this range improved significantly when using the VCD as compared to conventional real image displays. When using the VCD, the mean absolute percentage error (MAPE) and standard deviation in the pilots’ estimation of altitude in the range of 9.1 m to 18.3 m decreased by approximately 56.8% and 57.2%, respectively, signaling a significant improvement in the efficacy of flight simulation display systems with regard to visual depth cues.