22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-6.9.4

NEAL-SMITH CRITERIA-BASED HOO APPROACH TO PREDICTING AIRCRAFT HANDLING QUALITIES

N. Goto (1), T. Hoshizaki (2)
(1) Kyushu University, Fukuoka 812-8581, Japan; (2) Purdue University, West Lafayette, Indiana 47907-1282, USA

Keywords: neal-smith criteria, h-infinity model, control rate

The Neal-Smith criteria for assessing handling qualities of highly augmented aircraft have been transformed into an H8 -mixed-sensitivity norm. The norm features a control rate related term to account for the roll-off characteristic of the human pilot. The pitch attitude control is formulated as a mixed-sensitivity problem, which is solved by the model matching technique to yield H 8 -optimal pilot models. It is shown that the H8 -optimal pilot models well characterize the human pilot’s linear control behavior, and the resulting complementary sensitivity function meets the Neal-Smith criteria satisfactorily. Based on this result, a method is proposed to correlate the pilot rating data of the Neal-Smith flight test with the pilot compensation efforts manifested by the H8 -optimal pilot model. It is shown that a pair of measures from the H8 - optimal pilot model, maximum gain gradient and phase at the bandwidth frequency, can clearly divide the experimental pilot ratings into three levels.

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