Full-envelope, six-degrees-of-freedom trim analysis of unmanned aerial systems based on piece-wise polynomial aerodynamic coefficients

Polynomial models for the aerodynamic coefficients are not able to incorporate the full-envelope aerodynamics and offer only vaguely fitting at high angles of attack. In this paper, we propose a novel approach, namely piece-wise polynomial identification; this method provides a systematic approach for full-envelope aerodynamic fitting, considering measurements both of the pre-stall and post-stall region. As a result, a six-degrees-of-freedom, full-envelope analysis of trim conditions has successfully been applied for a large unmanned aerial vehicle.