Aerodynamic Coefficients Estimation of a Flight Vehicle From Different Flight Trials Under Limited Measurements

Abstract

An important applications of stochastic optimization techniques in aerospace science is aerodynamic coefficients estimation from flight data. Though plenty of literature exists for aircraft on this topic, is scanty for flight vehicles. Some of the authors developed an unified methodology of aerodynamic coefficients estimation of flight vehicles under practical constraints of limited measurements and mild excitations during flight. They have extensively validated this unified parameter estimation method using real flight data of different types of strategic and tactical flight vehicles. In this paper, they wish to share their recent experiences from different flight data of a tactical flight vehicle of two different configurations under development. In ballistic flight trials, the available measurements were position data obtained from electro optical tracking station and tracking radar as external measurements. In subsequent flight trials, the available on board measurements were noisy telemeter accelerometer and gyro signals with no external measurements. Present set of flight extracted aerodynamic coefficients are from separately three and two sets of flight tests of two similar configurations in presence of similar practical constraints. The flight estimated aerodynamic coefficients are axial force coefficient, moment coefficients due to angle of attack and control surface deflections and roll channel aerodynamic characteristics with respect to flight Mach Number. Very good consistency exists between extracted aerodynamic coefficients from different flight tests of same flight vehicle and once again overall estimation methodology under constraints of limited measurements is validated.

Aerodynamic Parameter Estimation of RLV from Telemeter Sensor Output

“…So limited sensor and mild maneuver throws challenge on APE of FV. The aerodynamic parameters estimated for different TFVs and SFVs were aerodynamic coefficients (ar) as a part of PFA [4,5]. Present research is extension of above activities for an Experimental Reusable Launch Vehicle (RLV).…”