An experimental investigation of VTOL flying qualities requirements in shipboard landings

Radford, R. C.; Andrisani, Dominick; Beilman, J. L.

doi:10.2514/3.44975

Cited by 6 publications

(5 citation statements)

References 1 publication

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“…These regions, not surprisingly, correspond in shape to the regions found in Ref. 7. Figure 14 indicates level 1 flying qualities (PR<3.5) with an open square, level 2 (3.5 <PR<6.5) with a half-full square, and level 3 (PR >6.5) with a completely filled square.…”

Section: Correlation With Flying Qualitiessupporting

confidence: 62%

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A nonlinear pilot model for hover

Andrisani

Gau

1985

Journal of Guidance, Control, and Dynamics

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This paper deals with persistent oscillations in position and attitude observed in flight on a piloted VTOL during precision hover. Properties of the oscillation are shown to correlate strongly with Cooper-Harper pilot ratings. A simple yet nonlinear pilot model is developed which predicts many of the properties of the pilot-inthe-loop system behavior. Configuration 217CK+ N(E) PR ll s Tx Nomenclature = properties of the ideal relay with dead zone (Af=0.25 in., >1 =0.125 in.) = configuration C of X-22A flight 217 = error in X position, -X C -X (ft) = amplitude of sinusoidal input to nonlinear element N(E) = pilot position error gain (in./ft) = ratio of steady state x translational velocity per inch of pilot's stick position (ft/s/in.) . = minimum pilot position error gain to maintain a stable limit cycle (in./ft) = describing function gain which is a nonlinear function of sinusoidal input amplitude E = Cooper-Harper pilot rating (Ref. 1) = quantization nonlinearity, Fig.9 = Laplace operator for differentiation = equivalent path mode time constant, s = fore and aft position, ft = commanded position, ft = pilot's stick position (positive stick aft, in.) -modified stick position (positive stick forward, in.) = -d s = body-axis pitch attitude, deg = limit-cycle frequency

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Section: Correlation With Flying Qualitiessupporting

confidence: 62%

“…8. It is proposed that the following properties of the pilot-in-the-loop system correlate with handling qualities as shown in Table 7.…”

mentioning

confidence: 99%

A nonlinear pilot model for hover

Andrisani

Gau

1985

Journal of Guidance, Control, and Dynamics

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“…Piloted simulation using advanced response types such as ACVH and TRC/PH during helicopter ship operations indicated best performance while workload decreased. Almost Level 1 handling qualities and minimized pilot workload were achieved as supported by time domain metrics [24] [25]. However, flight tests identified DVEs on pilot workload as first limits for safe operation [26]: DVE and turbulence increased workload and reduced piloting performance, and had an impact on control input activity.…”

Section: Literature Reviewmentioning

confidence: 98%

Piloted Simulation of Helicopter Shipboard Recovery with Visual and Control Augmentation

Mehling

Halbe

Gasparac

et al. 2021

AIAA Scitech 2021 Forum

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Shipboard launch and recovery of helicopters continue to pose operational challenges even for experienced pilots. The factors affecting pilot workload include unsteady ship motion, the influence of ship air wakes on helicopters, insufficient visual cues, and adverse weather conditions. The goal of the current research is to investigate novel visual and control augmentation techniques and evaluate their impact on pilot workload and handling qualities for shipboard recovery operations. This paper first outlines a helicopter-ship dynamic interface model developed and integrated into our existing rotorcraft simulation environment (ROSIE). It then describes a visual augmentation concept using a see-through helmet-mounted display (HMD) system for enhancing the pilot's visual cueing environment during the shipboard approach and landing tasks. Next, it describes the synthesis of robust nonlinear control laws for achieving advanced helicopter response types with predicted Level 1 handling qualities. Lastly, the paper reports the results of simulation tests of maritime mission task elements by four experimental test pilots with different levels of augmentation and under different environmental conditions. Results on navigation performance, workload indices, and handling quality ratings indicate a decreased workload and improved handling qualities to almost Level 1 with the assistance of the visual and control augmentation system. Moreover, all piltos stated a higher situational awareness while operating in degraded visual environment conditions using visual and control augmentation.

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“…The definitions of bandwidth and phase delay used in Table 2 22 and was classified as "desired" in Ref. 23.…”

Section: Control System Response Identificationmentioning

confidence: 99%

Control and display combinations for blind vertical landings

Schroeder

Merrick

1992

Journal of Guidance, Control, and Dynamics

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Several hover control and display concepts were evaluated in flight on a variable-stability helicopter. The control and display concepts enable precise hover maneuvers, station keeping, and vertical shipboard landings in zero-visibility conditions and until now have been evaluated only in piloted simulations. A new display design method is presented that attempts to attain the same pilot-vehicle performance regardless of the level of control augmentation. The display design method was first examined analytically with the control dynamics in the context of the pilot's desired guidance strategy. Then, while fully hooded, three pilots performed landing-pad captures followed by vertical landings with attitude-rate-command/attitude-hold, attitude-command/attitudehold, and translational-velocity-command control systems. Of the 28 piloted blind landings, 25 were within 5 ft and 14 were within 2 ft of the specified touchdown point.

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An experimental investigation of VTOL flying qualities requirements in shipboard landings

Cited by 6 publications

References 1 publication

A nonlinear pilot model for hover

A nonlinear pilot model for hover

Piloted Simulation of Helicopter Shipboard Recovery with Visual and Control Augmentation

Control and display combinations for blind vertical landings

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