Simulating self-motion

In general, vehicle motions far exceed the mechanical constraints of an earth-fixed simulator base. Inertial motions can, therefore, only be simulated in partial agreement with those of the actual vehicle. As a consequence, physical mismatches between inertial and environmental motion are inevitable. Here, the concept of a subjective reference frame is introduced, relative to which perceived self-motion is defined. This frame must be released from the earth-fixed frame to evoke simulated self-motion. In addition, self-motion and environmental motion need to be perceived reciprocal, in order to evoke a stationary perceived environment. Due to the only limited accuracy of human self-motion perception, however, perceived self-motion and perceived environmental motion need not to be exactly reciprocal. The extent to which self-motion and environmental motion may differ can be expressed by a just noticeable difference. This just noticeable difference denotes the threshold at which the environment is perceived to move. In this article, a self-motion perception model is outlined in which perceived environmental motion and perceived self-motion are separated. The perception model and the just noticeable differences can then be applied to determine the inertial stimulation that is needed to evoke perceived self-motion, in which the environment is perceived stationary throughout simulation.