Flying by Feeling: Communicating Flight Envelope Protection through Haptic Feedback

Abstract

Modern aircraft can be equipped with a flight envelope protection system: automation which modifies pilot control inputs to ensure that the aircraft remains within the allowable limits. Overruling the pilot inputs may lead to mode confusion, even when visual or auditory feedback is provided to alert pilots. We advocate using active control devices to make the flight envelope protection system tangible to the pilot. This paper presents the main findings of an evaluation of three haptic feedback designs for flight envelope protection. The first concept used both force feedback and vibro-tactile alerts, producing promising, yet inconclusive, results. The second concept used asymmetric vibrations to give directional alerting cues, which did not result in improved performance on initial use, but which did yield improved learning rate for the task. The third system employed force feedback to physically guide the pilot away from flight envelope limits, which yielded safety improvements from the first use, but created dependence: pilot performance degraded immediately after the force feedback was removed. From this, we advise to use asymmetric vibrations during training for flight envelope excursions, to leverage active control interfaces for providing force feedback during operation, and reevaluate a combination of both to combine their advantages for single-pilot operations.

Low-visibility commercial ground operations: An objective and subjective evaluation of a multimodal display

“…Studies where an effect of haptics been absent often communicate task-related information with discrete arbitrary signals that bear minimal resemblance to users' existing mental models. For instance, a recent study by Van Baelen et al [41] in 2021 found no performance benefit associated with the representation of departing a safe flight envelope through the presentation of a discrete saw-tooth vibrotactile signal. In the current study, this observation was echoed within participant comments on the lack of intuitiveness of the lateral proprioceptive cues relative to the distance to turn vibrotactile cue.…”

More Haptic Aircraft

“…Recent research undertakings are also geared towards enhancing haptic feedback in fly-by-wire controls. For instance, Van Baelen et al [19] presented flight envelope protection through haptic feedback, incorporating both force and vibrations in the control stick. This system assists pilots in evading flight envelope speed and load factor threshold values, especially when there is a shift to an alternative control law.…”

Planning lane changes using advance visual and haptic information

“…For instance, Navarro et al (2007Navarro et al ( , 2010 developed and tested a haptic hybrid warning-guidance device called motor priming (MP) designed to help drivers keep their lane. The MP device generates asymmetrical movements on the steering wheel such that the amplitude in the direction of the lane center is larger than the amplitude in the direction of lane departure (see also Van Baelen et al, 2021). In a series of experiments (Navarro et al, 2007(Navarro et al, , 2010, the efficacy of the MP device was compared with a range of warning systems, consisting of an auditory warning (a rumble strip sound), symmetrical (i.e., directionless) steering wheel oscillations, lateral vibrations on the steering wheel (two vibrators were inserted in the upper part of the steering wheel, one on each side), and lateral vibrations on the seat (a set of vibrators was placed in the right and left sides of the base and back of the seat).…”