An analytical and flight-test approach to the reduction of pilot-induced oscillation susceptibility

Abstract

FEW = effective bobweight force, Ib FE = force error signal, Ib Fs = pilot's applied force, Ib fn = undamped natural frequency, cps g = gravitational acceleration constant, ft/sec GI = inner loop transfer function, gr/lb Gp = pilot's transfer function, Ib/gr j = (-1)1/2 Kp = pilot's gain, Ib/deg \BW = distance from center of gravity to the mass center of the bobweight effectiveness, ft 1 panei = distance from center of gravity to the front cockpit, ft Nz = normal load factor, g s = Laplace operator d/dt, X TN = neuromuscular lag of pilot's transfer function, sec T8 = hydraulic servo valve time constant, sec dH = horizontal stabilizer displacement, deg d$ = longitudinal stick displacement, in. f = damping ratio w = circular frequency, rad/sec wn = undamped natural circular frequency, rad/sec WD = natural damped circular frequency, rad/sec T = pilot's reaction time constant, sec do = pitch angle output of loop, deg 0/ = pitch angle input of loop, deg