Analysis of a reversible flight control system response to atmospheric turbulence

摘要

A mathematical model was developed for the reversible longitudinal control system of a regional commuter aircraft using the available geometry, mass property and kinematics. The model was incorporated into a general multi-body dynamics code and validated using existing manufacturer's data as well as recorded data from several flights. Analysis of the flight data revealed light atmosphere turbulence level. To investigate the effect of higher turbulence intensity on the reversible flight control system, a sever turbulence level was generated using Von Karman model for the same flight level and velocity. The result was used as a random input to the dynamic model for computation of the frequency response of control column. It was shown that turbulence could act as a random input through the hinge moment during the flight and introduced a new mode in the lower end of power spectral density curve. The energy induced by this low frequency input resulted in large displacement of control column in simulation which surpassed the existing limits. Therefore it should be taken into account when dealing with handling quality as well as autopilot design.