Development of a Dynamic Model of a Generalised Combat Aircraft with Forward Wings for the Identification of Stability and Control Characteristics

摘要

A forward swept wing aircraft was designed theoretically and then dynamically scaled down to suit the Weybridge wind tunnel facility. The model is then made to fly in four degrees of freedom, namely, pitch, yaw, roll and vertically up and down. Transient response of this model to dipole deflection of the canard, ailerons or rudder are recorded in the computer memory after digitization through an interface. Later, these data are read from the memory into the extended Kalman filter program together with the estimates of relevant aerodynamic derivatives serving as initial values. The output, provided the filter does not diverge, would be the identified aerodynamic derivative parameters. The confidence level can then be checked by inserting these values into a simulation program written in ACSL. The transient response of this simulated model is then checked against the experimental one. If the two traces coincide, it can be said that the values of identified parameter are close to the actual values.