Effects of Heave Washout Filtering on Motion Fidelity and Pilot Control Behavior for a Large Commercial Airliner

Abstract

Due to the significant translational heave motion at the pilot station associated with changes in aircraft pitch attitude, the motion cueing for aircraft pitch maneuvering typically requires significant heave washout filtering. Previous studies that attempted to motivate choices in the motion cueing strategy for pitch maneuvering based on measurements of pilot behavior. For the small conventional aircraft considered in these studies, the results indicated that, despite the fact that pilots were found to adapt their control strategy to changes in heave cueing, the pitch rotation had a dominant influence on pilot behavior during pitch tracking. For large commercial airliners, a relevant application of this research as a lot of commercial pilot training occurs on moving-base simulators, the location of the pilot station is significantly further from the center of aircraft pitch rotation, yielding more pronounced heave motion cues during changes in pitch attitude. This difference, in addition to typically slower pitch dynamics that require more lead equalization, implies the best choice in motion cueing for large aircraft may be significantly different from what would be optimal for smaller aircraft. In this paper, an experiment is described in which pilot behavior is measured in a pitch attitude disturbance-rejection task with a controlled element and motion cueing conditions that are representative for a Boeing 747 aircraft. Different third-order heave washout filter settings were considered, in addition to a variation in the presence of 1-to-1 rotational pitch motion. Significant effects of the applied variation in pitch and heave motion cueing are observed, even though the effect of heave motion feedback is indeed found to be comparatively more important for larger aircraft. Furthermore, a heave motion filter that combined a low gain with low filter phase distortion was found to yield the least effect on pilot behavior, while for heave motion filters with a relatively high gain and high break frequency significantly larger contributions of motion feedback to pilot behavior were observed.

Tuning Models of Pilot Tracking Behavior for a Specific Simulator Motion Cueing Setting

“…Even though the trend in this dependent measure is not as large as those found for K v and T L (only 7% variation for K S ranging from 0 to 1), still a highly 12 consistent increase in τ v is observed with increasing K S . This effect is often seen to occur in series with a reduction in the amount of visual lead equalization (lower T L ), and is believed to result from the fact that due to the added information from motion feedback, a control strategy that requires less workload, but induces more high-frequency phase lag in the pilot visual control response H pv (jω), is permissible without significant effect on the dominant closed-loop characteristics.…”

“…This trend is consistent over studies in which the controlled element state is the dominant motion cue that is perceivable to the pilot. For control tasks for which this is not the case, most notably for pitch tracking tasks with conventional aircraft as considered in a number of previous studies, 9,12,25 where heave motion is the dominant motion cue rather than rotational pitch motion, an opposite trend in T L is observed. This is believed to be a result of the fact that this heave motion provides less useful motion feedback to pilots than only rotational pitch motion would.…”

“…(12) and (13), also other evaluation frequencies -such as 0.5 and 2, and 3 rad/s -were considered as fidelity metrics in this study. This paper, however, will only analyze trends in the dependent measures as a function of K S and φ S , as the other evaluation frequencies were not found to yield markedly different results for the considered set of experimental measurements.…”

“…4,8 This paper provides the first result of our effort in compiling data from a number of experiments from which measurements of multimodal pilot behavior under varying motion cueing conditions are available. Data have been collected from a number of investigations performed at Delft University of Technology 7,[9][10][11][12] and from a number of studies found in literature. 4,8,[13][14][15] This paper will provide a short overview of the scope and setup of all these different experiments.…”

Are Criteria for Motion Cueing and Time delays possible? Part 2

“…Delft University performed two simulator experiments to investigate the influence of motion feedback for the pitch control task 24,25 . The first experiment 24 Seven subjects participated into the tracking experiment.…”