Time-Varying Manual Control Identification in a Stall Recovery Task under Different Simulator Motion Conditions

Abstract

This paper adds data to help the development of simulator motion cueing guidelines for stall recovery training by identifying time-varying manual control behavior in a stall recovery task under different simulator motion conditions. A study was conducted with seventeen general aviation pilots in the NASA Ames Vertical Motion Simulator. Pilots had to follow a flight director through four stages of a high-altitude stall task. A time-varying identification method was used to quantify how pilot manual control parameters change throughout different stages of the task in both roll and pitch. Four motion configurations were used: no motion, generic hexapod motion, enhanced hexapod motion and full motion. Pilot performance was highest for the enhanced hexapod and full motion configurations in both roll and pitch, and the lowest without motion. In the roll axis, the pilot position gain did not significantly change throughout the stall task, but was the lowest for the condition with no motion. The pilot roll velocity gain was significantly different between motion conditions, the largest difference being found close to the stall point. The enhanced hexapod motion condition had the highest pilot roll velocity gain. In the pitch axis, the pilot position gain was significantly different between time segments but not between motion conditions. The pilot pitch velocity gain was highest for the full motion condition and increased close to the stall point, but did not change significantly for the other motion conditions. Overall, pilot control behavior under enhanced hexapod motion was most similar to that under full aircraft motion. This indicates that motion cueing for stall recovery training on hexapod simulators might be improved by using the principles behind the enhanced hexapod motion configuration. configurations similar to those in a previous experiment. 20 The generic hexapod motion condition ( GH ) had motion similar to what current hexapod training simulators provide. The enhanced hexapod motion condition ( EH ) eliminated translational c.g. accelerations to allow for increased fidelity of the translational accelerations as a result from rotations about the c.g. and the rotational accelerations themselves; that is, EH had a higher fidelity of the motion cues most important for aircraft control during the stall task compared to GH . For tracking tasks with controlled elements requiring lead equalization, such as the aircraft dynamics used in this study, motion feedback is used by human controllers to reduce the amount of visually generated lead, allowing for better disturbance-rejection performance. 24 The extent to which motion feedback is used is affected by the fidelity of motion stimuli important to the task. Attenuation of these motion cues, either by scaling or high-pass filtering, results in human manual control with lower gains and increased reliance on visual lead, which typically results in worse disturbance-rejection performance. As the stability of the aircraft dynamics decreases closer to the stall point, motion becomes more important to maintain a certain level of performance. A new pilot control behavior identification technique based on a DEKF was used for the first time to investigate how pilot model parameters vary during a stall maneuver under the different motion configurations. Based on these considerations, the literature, and test runs in the VMS, the following hypotheses were formulated: simple main effect of that K v in pitch did not significantly change at t 1 between NM GH ( p = 0 . 216 ), and EH ( p = 1 . 000 ). It significantly increased from 0.009 in NM to 0.012 in FM ( p = 0 . 001 ). The pitch velocity gain significantly decreased from 0.11 in GH to 0.009 in EH for t 1 ( p = 0 . 003 ). There was a significant increase from 0.009 in EH to 0.012 in FM ( p < 0 . 001 ). For t 2 , the pitch velocity gain did not significantly change between NM and GH ( p = 1 . 000 ) and EH ( p = 1 . 000 ); however, it significantly increased from 0.011 in NM to 0.016 in FM ( p = 0 . 002 ). K v did not significantly change between GH and EH at t 2 ( p = 0 . 278 ), but it significantly increased from 0.012 in GH to 0.016 in FM ( p = 0 . 002 ). There was also a significant increase from 0.011 in EH to 0.016 in FM ( p < 0 . 001 ). At t 3 , there was no significant change in the pitch velocity gain between NM and GH ( p = 0 . 165 ) and EH ( p = 1 . 000 ), however it significantly increased from 0.009 in NM to 0.013 in FM ( p = 0 . 001 ). There was no significant change between GH and EH ( p = 0 . 147 ) and FM ( p = 0 . 093 ). The pitch velocity gain significantly increased from 0.009 in EH to 0.013 in FM ( p < 0 . 001 ). For the last time segment, t 4 , K v did not significantly change between NM and GH ( p < 0 . 065 ) and EH ( p = 1 . 000 ), but significantly increased from 0.009 in NM to 0.012 in FM