Rotorcraft flight endurance estimation based on a new battery discharge model

To avoid the numerical complexities of the battery discharge law of electric-powered rotorcrafts, this study uses the Kriging method to model the discharge characteristics of Li-Po batteries under standard conditions. A linear current compensation term and an ambient temperature compensation term based on radial basis functions are then applied to the trained Kriging model, leading to the complete discharged capacity-terminal voltage model. Using an orthogonal experimental design and a sequential method, the coefficients of the current and ambient temperature compensation terms are determined through robust optimization. An endurance calculation model for electric-powered rotorcrafts is then established, based on the battery discharge model, through numerical integration. Laboratory tests show that the maximum relative error of the proposed discharged capacity-terminal voltage model at detection points is 0.0086, and that of the rotorcraft endurance calculation model is 0.0195, thus verifying their accuracy. A flight test further demonstrates the applicability of the proposed endurance model to general electric-powered rotorcrafts.