Subjective Estimates of G-load in Centrifuge-Based Simulation and Applications for G-cueing in Desdemona

In centrifuge simulators pilots experience the G-forces and fast G-onsets encountered in the real fighter aircraft. The motion cueing principle that drives these simulators is based on creating G-forces by increasing the centripetal force of the centrifuge through a rotation of the simulator arm. The centrifuge usually spins at a constant 1.4 G baseline G-level when the aircraft is level and stationary. Ideally, the motion cueing algorithm presents to pilots a G-vector that is equal to the real one both in direction and amplitude. This motion cueing principle assumes that the pilots perceive any deviation from the desired G-load. If this is not true, one could reduce the high angular accelerations/decelerations of the centrifuge arm since there is no need to reach the exact airplane G-load. This would then reduce the negative side-effects (like motion sickness) that come from the high angular accelerations/decelerations in short-radius centrifuges. We investigated the just noticeable differences (JND) in the perception of G-load magnitude. The study was conducted in the Desdemona research simulator where eleven subjects participated in the experiment. Subjects actively had to reproduce a G-load that was passively presented to them. Two G-loads were presented to the subjects (1.6 G and 1.8 G). Results showed that subjects have a better accuracy in reproducing the 1.6 G than the 1.8 G condition. This indicates that the JND in perceiving the magnitude of the G-load is related with the G-load intensity. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.