Bell 412 System Identification and Model Fidelity Assessment for Hover and Forward Flight

Seher-Weiß, Susanne; Tischler, Mark B.; Scepanovic, Pavle; Gubbels, Arthur

doi:10.4050/jahs.66.012004

Cited by 6 publications

(9 citation statements)

References 0 publications

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“…𝑀 is removed from both approaches, due to the weakly-excited yaw motion impacting the pitch acceleration. Moreover, the ASysID results are close to those derived independently using the frequency-domain approach as previously reported in [12]. Secondly, there are larger differences among the off-axis derivatives, e.g., 𝐿 and 𝑀 , that are both predicted with an opposite sign by the LF-B412 w/o MWD, compared with the ASysID estimates.…”

Section: B Estimation Resultssupporting

confidence: 85%

“…The identification of higher-order models of the Bell 412 accounting for flapping dynamics in the frequency domain has been reported in Ref. [12].…”

Section: A Assumed Model Structurementioning

confidence: 99%

“…In the former, identification of a model is usually performed using control frequency sweeps, while the latter typically uses multi-step control inputs such as doublets, 3211/2311s etc. The approach has been used extensively for fixedwing aircraft [1,6], unmanned aircraft [7][8][9], and rotorcraft [2,[10][11][12][13] for performance and handling qualities evaluation, control law development, aircraft dynamic loads analysis, dynamic inflow modelling, and the creation of models for use in piloted simulation environments. SysID has been applied as an effective approach for informing these tuning processes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A New Heuristic Approach to Rotorcraft System Identification

Agarwal²,

Padfield

et al. 2023

j am helicopter soc

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High-fidelity rotorcraft flight simulation relies on the availability of a quality flight model that further demands a good level of understanding of the complexities arising from aerodynamic couplings and interference effects. This paper explores rotorcraft flight dynamics in the low-speed regime where such complexities abound and presents a new heuristic approach in the time domain to aid identification of nonlinear dynamics and fidelity assessment. The approach identifies flight model parameters “additively,” based on their contribution to the local dynamic response of the system, in contrast with conventional approaches where parameter values are identified to minimize errors over a whole maneuver. In these early investigations, identified low-order, rigid-body, linear models show good comparison with flight-test data. The approach is extended to explore nonlinearities attributed to the so-called maneuver wake distortion and wake skew effects emerging in larger maneuvers. The results show a good correlation for the proposed nonlinear model structure, demonstrated by its capability to capture the time response and variations of the stability and control derivatives with response magnitude.

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Section: B Estimation Resultssupporting

confidence: 85%

“…The identification of higher-order models of the Bell 412 accounting for flapping dynamics in the frequency domain has been reported in Ref. [12].…”

Section: A Assumed Model Structurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A New Heuristic Approach to Rotorcraft System Identification

Agarwal²,

Padfield

et al. 2023

j am helicopter soc

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“…Details and results of the identified model in hover can be found in Seher-Weiß et al (Ref. 23). The hover model was identified using the CIFER ® frequency response method detailed in Tischler and Remple (Ref.…”

Section: Bell 412: Simulation Model Improvements In Hovermentioning

confidence: 99%

Simulation Model Fidelity Enhancement Using Corrective Force and Moment Increments - Review of Activity Performed in NATO-AVT Panel 296

Myrand-Lapierre¹,

Yavrucuk²,

Richard³

et al. 2021

Proceedings of the Vertical Flight Society 77th Annual Forum

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The Applied Vehicle Technology (AVT) Panel of the NATO Science and Technology Organization has recently engaged a Research Task Group on the topic of rotorcraft flight simulation model fidelity. This group aimed to explore a comprehensive set of methods for flight mechanics simulation fidelity enhancement, including training simulation applications. Particular effort was also directed to the metrics used for simulation fidelity model assessment as suitable for the final intent of the model. The work presented in this paper was carried out in the framework of this Research Task Group, AVT-296, which examined seven different approaches; our paper focusses on just one of these. The objective was to assess flight-model renovation methods through four different applications. As a common approach, flight data from various helicopters were used to extract a set of flight dynamics information (state and control derivatives) that were used to compute corrective force and moment terms. The approach consists of a comparison between flight-test and flight mechanics model derivatives to compute delta forces and moments. These delta terms are added to the forces and moments through a linear combination and to generate the additional accelerations needed to capture any lacking dynamics. The derivatives that require updating need to be identified and, of course, will depend on the nature of the modelling deficiency. This paper shows how this method is applied to enhancing the lateral-directional oscillatory characteristics of flight models and how they can be upgraded to achieve higher fidelity for design and development applications but with special attention to meeting the fidelity requirements for flight training simulators.

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“…1 Possible "black box" update models simulation models (so-called hybrid modeling) is utilized. In [11], a system identification model of the aircraft was used to calculate the desired input filter for a linear simulator model by algebraic inversion. This paper extends and implements this approach to the nonlinear simulator model.…”

Section: Introductionmentioning

confidence: 99%

Improving a real-time helicopter simulator model with linear input filters

Scepanovic

Döring

2021

CEAS Aeronaut J

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For a broad range of applications, flight mechanics simulator models have to accurately predict the aircraft dynamics. However, the development and improvement of such models is a difficult and time consuming process. This is especially true for helicopters. In this paper, two rapidly applicable and implementable methods to derive linear input filters that improve the simulator model are presented. The first method is based on model inversion, the second on feedback control. Both methods are evaluated in the time domain, compared to recorded helicopter flight test data, and assessed based on root mean square errors and the Qualification Test Guide bounds. The best results were achieved when using the first method.

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Bell 412 System Identification and Model Fidelity Assessment for Hover and Forward Flight

Cited by 6 publications

References 0 publications

A New Heuristic Approach to Rotorcraft System Identification

A New Heuristic Approach to Rotorcraft System Identification

Simulation Model Fidelity Enhancement Using Corrective Force and Moment Increments - Review of Activity Performed in NATO-AVT Panel 296

Improving a real-time helicopter simulator model with linear input filters

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