Human Transfer Functions for Multi-Axis and Mltlti-Loop Problems

Adams, J. J.

doi:10.2514/6.1965-1521

Cited by 5 publications

(3 citation statements)

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“…Multiple investigations have clearly found a degradation in performance with dual axis in comparison to single axis tasks [1], [7], [17]. In fact, the relation between crossover frequency (the frequency up to which the HC is able to track) and the number of axis was postulated to be proportional to the reciprocal of the square root of the number of axis [18]. That is, with dual axes, the crossover frequency is 1/ √ 2 of that of the single axes case.…”

Section: Introductionmentioning

confidence: 99%

Dual-Axis Manual Control: Performance Degradation, Axis Asymmetry, Crossfeed, and Intermittency

Barendswaard

Pool

Paassen

2019

IEEE Trans. Human-Mach. Syst.

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Vehicle control tasks require simultaneous control of multiple degrees-of-freedom. Most multi-axis human-control modeling is limited to the modeling of multiple fully independent single axes. This paper contributes to the understanding of multi-axis control behavior and draws a more realistic and complete picture of dual-axis manual control. A human-in-the-loop experiment was performed to study four distinctive phenomena that can occur in multi-axis control: performance degradation, axis asymmetry, crossfeed, and intermittency. In a simulator, three conditions were tested in the presence and absence of physical motion: the full dual-axis control task, single-axis roll task, and single-axis pitch task. Controlled element dynamics, stick dynamics, and forcing functions were equal in all cases. Results show that performance is worse in dual-axis tasks. Performance in roll axis is consistently worse than pitch, thereby proving axis asymmetry. Physical motion improves the performance and stability of the system. The application of independent forcing function signals in both controlled axes resulted in the detection of crossfeed in dual-axis tasks from spectral analysis. Using a novel extended Fourier coefficient method, the identified crossfeed dynamics can explain up to 20% of the measured control inputs and improves modeling accuracy by up to 5%. Dual-axis control behavior is less accurately modeled with linear time-invariant models and is more intermittent.

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Section: Introductionmentioning

confidence: 99%

Dual-Axis Manual Control: Performance Degradation, Axis Asymmetry, Crossfeed, and Intermittency

Barendswaard

Pool

Paassen

2019

IEEE Trans. Human-Mach. Syst.

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“…In Ref. 6 it is shown that in the multiloop control task of lunar module hover, where the outer-loop variable is horizontal translation and the inner-loop variable is pitch angle, that the series arrangement of the pilot model does give a true representation of human pilot response. In this task the outer-loop dynamics were where a small time delay is used instead of a lag function.…”

Section: Pilot Modelsmentioning

confidence: 99%

An Approac e Determination of Aircraft Handling Qualities Using Pilot Transfer Functions

Adams

Hatch

1971

Journal of Aircraft

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It is shown that a correlation exists between pilot-aircraft system closed-loop characteristics, determined hy using analytical expressions for pilot response along with the analytical expression for the aircraft response, and pilot ratings obtained in many previous flight and simulation studies. Two different levels of preferred pilot response are used. These levels are 1) a static gain and a second-order lag function with a lag time constant of 0.2 sec and 2) a static gain, a lead time constant of 1 sec, and a 0.2-sec lag time constant. If a system response with a pitch-angle time constant of 2.6 sec and a stable oscillatory mode of motion with a period of 2.5 sec can be achieved with the first level pilot model, it is shown that the pilot rating will be satisfactory for that vehicle. Further, if an altitude response with a stable oscillatory mode of motion with a period of 5 sec can be achieved, the vehicle will be rated satisfactory. If the second level pilot model is required to achieve these system response characteristics, the aircraft will be rated acceptable-unsatisfactory. Nomenclatureh = altitude, ft (m) K\ -pilot model static gain La. = normalized lift-force derivative, per sec L& e = normalized control-lift derivative, per sec M q = normalized damping-moment derivative in pitch, per sec M a = normalized pitching-moment derivative, per sec 2 Ms e = normalized pitching control-moment derivative, per sec 2 P h = closed-loop period of the altitude mode of motion, sec P a -closed-loop period of the angle-of-attack mode of motion, sec s = Laplace operator, per sec T -closed-loop time constant, sec TI = pilot model lead time constant, sec TI -pilot mo'del lag time constant, sec T$z -open-loop aircraft lead time constant, sec V = velocity, ft/sec (m/sec) x = displacement, ft (m) a. = angle of attack, rad 7 = flight-path angle, rad 8 = control deflection, rad e = displayed error, rad f = damping ratio £h -damping ratio of the altitude mode of motion £a = damping ratio of the angle-of-attack mode of motion B = pitch angle, rad wn = open-loop aircraft undamped natural frequency, rad/sec ojf = control actuator undamped natural frequency, rad/sec Subscripts c = command h = altitude = error = pitch

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“…If the control task is a multiloop problem, where there is a second variable (such as altitude or horizontal displacement) which is controlled by the manipulation of an innerloop variable (such as pitch angle), it is necessary to specify an outer-loop pilot model in It was also shown in reference 6 that the lag function included in the outer-loop pilot model is not really required to properly represent the pilot. The outer-loop variable (horizontal translation) is controlled at such a low frequency that a lag of the magnitude of 0.1 second does not influence the closed-loop response.…”

Section: Multiloop Control Tasksmentioning

confidence: 99%

An approach to the determination of aircraft handling qualities using pilot transfer functions

Adams¹,

Hatch²

1970

Propulsion and ASW Meeting

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Human Transfer Functions for Multi-Axis and Mltlti-Loop Problems

Cited by 5 publications

References 0 publications

Dual-Axis Manual Control: Performance Degradation, Axis Asymmetry, Crossfeed, and Intermittency

Dual-Axis Manual Control: Performance Degradation, Axis Asymmetry, Crossfeed, and Intermittency

An Approac e Determination of Aircraft Handling Qualities Using Pilot Transfer Functions

An approach to the determination of aircraft handling qualities using pilot transfer functions

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