Determination of Maximum Unnoticeable Added Dynamics

Mitchell, David G. M.; Hoh, Roger H.; He, Chengjian; Strope, Kristopher

doi:10.2514/6.2006-6492

Cited by 11 publications

(17 citation statements)

References 1 publication

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“…Consistent with knowledge of human manual control (McRuer and Jex, 1967), MUAD envelopes are narrow in the frequency range critical to manual control performance, and notably wider at low and high frequencies. Recently, it has been stressed by Mitchell et al (2006) that such envelopes depend on the dynamic characteristics -i.e., bandwidth -of the baseline (reference) vehicle dynamics, a dependency that would greatly complicate the task of defining universal envelopes for allowable levels of mismatch. Still, given their straightforward applicability and their intuitive soundness, the MUAD envelopes have become a de facto standard to assess the adequacy of LOES (Field et al, 2003;Bosworth and Williams-Hayes, 2007;Geluardi et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

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A Cybernetic Analysis of Maximum Unnoticeable Added Dynamics for Different Baseline Controlled Systems

et al. 2017

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Maximum unnoticeable added dynamics (MUAD) envelopes have been largely used to assess the adequacy of low-order equivalent systems (LOES) in handling qualities assessment and simulator validation. However, research has shown that more thorough verification of the adequacy of this method is required. This paper studies the influence of the baseline aircraft dynamics on the MUAD envelopes. The assessment is based on quantitative measures of pilot control behaviour obtained with the cybernetic approach. The measures were taken from a human-in-the-loop pitch tracking task experiment with compensatory display. The results are consistent with the MUAD envelopes and reveal no interaction effects of the baseline and added dynamics on the pilot control behaviour. This suggests that, under the considered conditions, the MUAD envelopes shall remain constant independently of the bandwidth of the baseline controlled dynamics.

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Section: Introductionmentioning

confidence: 99%

“…MUAD envelopes are traditionally determined from extensive human-in-the-loop experiments, where subjective ratings are used to determine the noticeability of added dynamics (Wood and Hodgkinson, 1980;Mitchell et al, 2006). The main drawback of subjective assessment methods is their poor reproducibility.…”

Section: Introductionmentioning

confidence: 99%

A Cybernetic Analysis of Maximum Unnoticeable Added Dynamics for Different Baseline Controlled Systems

et al. 2017

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“…The handling qualities community has defined a region of maximum unnoticeable added dynamics (MUAD). [8][9][10] Flighttesting has shown that if the system response is within the MUAD envelope the response is indistinguishable from the lower-order system. Thus, one metric used to assess the effectiveness of the adaptation system was to show how well the system with adaptation compared to the MUAD envelope.…”

Section: A Technical Performance Metricsmentioning

confidence: 99%

Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

Bosworth

Williams-Hayes

2007

AIAA Infotech@Aerospace 2007 Conference and Exhibit

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Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented. Nomenclature

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“…The handling qualities community has defined a region of maximum unnoticeable added dynamics (MUAD). [11][12][13] The MUAD envelope is computed for a given lower-order system (in our case the onboard reference model). Flight-testing has shown that if the system response is within the MUAD envelope the response is indistinguishable from the lower-order system.…”

Section: B Closed-loop Metricmentioning

confidence: 99%

Flight Results of the NF-15B Intelligent Flight Control System (IFCS) Aircraft with Adaptation to a Longitudinally Destabilized Plant

Bosworth

2008

AIAA Guidance, Navigation and Control Conference and Exhibit

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Adaptive flight control systems have the potential to be resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. The goal for the adaptive system is to provide an increase in survivability in the event that these extreme changes occur. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane. The adaptive element was incorporated into a dynamic inversion controller with explicit reference model-following. As a test the system was subjected to an abrupt change in plant stability simulating a destabilizing failure. Flight evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to stabilize the vehicle and reestablish good onboard reference model-following. Flight evaluation with the simulated destabilizing failure and adaptation engaged showed improvement in the vehicle stability margins. The convergent properties of this initial system warrant additional improvement since continued maneuvering caused continued adaptation change. Compared to the non-adaptive system the adaptive system provided better closed-loop behavior with improved matching of the onboard reference model. A detailed discussion of the flight results is presented. Nomenclature

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Determination of Maximum Unnoticeable Added Dynamics

Cited by 11 publications

References 1 publication

A Cybernetic Analysis of Maximum Unnoticeable Added Dynamics for Different Baseline Controlled Systems

A Cybernetic Analysis of Maximum Unnoticeable Added Dynamics for Different Baseline Controlled Systems

Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

Flight Results of the NF-15B Intelligent Flight Control System (IFCS) Aircraft with Adaptation to a Longitudinally Destabilized Plant

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