Fighting False Forces

Abstract

For helicopter pilots, motion feedback is essential to fly the aircraft precisely. Supplying pilots with motion cueing is therefore an important issue in flight simulators. The main problem is the limited space envelope of motion systems that strictly constrains the direct provision of translational accelerations. Consequently, those signals need to be transformed to angular attitudes or scaled down depending on the time range they appear. This task is fulfilled by motion controls using sets of high- and low-pass filters in combination with gain factors. But state-of-the-art control methods typically do not distinguish the different causes of accelerations due to flight maneuvers. From a pilot point of view this leads to simulated helicopter responses that differ from the real aircraft. With the Apparent Vertical Filter a new concept was developed by the German Aerospace Center (DLR) to address this issue.