Equilibrium stability of a servo actuating flight controls in a servoelastic framework.

The mounting structure stiffness’s effects on mecanohydraulic servomechanisms actuating aicraft’s primary flight controls are modeled as a system of ordinary differential equations. Stability analysis of equilibria reveals the presence of a critical case that is handled through the use of the Lyapunov-Malkin theorem. Stability charts are drawn using the RouthHurwitz criterion for stability polynomial and it is shown that the stability of the system can be ensured exploiting positive influence of structural feedback. 2000 Mathematics Subject Classification: 34H05, 34D20.