飞行仿真中气动特性数据拟合方法研究

飞机气动特性数据是飞行仿真的基础,其精确性直接影响着飞行仿真效果.提出一种基于遗传算法的B样条曲线拟合方法,建立了飞机气动特性数据的数学模型.B样条曲线可对复杂曲线进行拟合,但数据点的参数选择影响着拟合的精度.参数选择通常有两种方法,一种是固定B样条基的节点选择参数,另一种是选定参数然后变化B样条基的节点.采用遗传算法将二者统一考虑,同时变化节点与参数使得拟合误差最小.通过气动特性数据拟合验证了该方法的有效性、精确性和鲁棒性.

On curve fitting method of aerodynamic data in flight simulation

Aerodynamic data of aircraft are the basis for flight simulation and the effect of flight simulation is affected by the precision of aerodynamic data.The method of B-spline curve fitting based on genetic algorithm is put forward and the mathematic models of aerodynamic data are established.Complicated curve can be fitted by B-spline curve,but curved-fitting precision is influenced by parameter selection of data points.There are usually two methods for parameter selection.One is to choose parameters when the knots of the B-spline bases are fixed,the other is to fix parameters in advance and then to calculate the knots of the B-spline bases.Both the parameters and the knots of the B-spline bases are considered by using genetic algorithms.The parameters and the knots of the B-spline bases are computed at the same time to obtain the minimum fitting error.The validity,precision and robustness of the method are demonstrated by aerodynamic data fitting.