基于最优节点样条逼近的水泵特性曲线拟合方法

Fitting method for pump characteristic curve based on optimal knots spline approximation

本文将三次均匀B样条方法应用于多种水泵特性曲线的拟合,能够在同一拟合函数下适应曲线形状多变的情况。根据离散数据点连线的几何形状将其分成形状简单的几段,在最小二乘意义下分步优化节点的横坐标和纵坐标,得到了最优逼近的样条曲线。通过实例计算表明,该方法可以较好地将多种水泵试验数据拟合成光滑的特性曲线,并能够消除因试验数据随机误差所引起的曲线扰动。

A Fitting method for pump characteristic curves of various geometries based on cubic uniform B spline is presented in this paper. Under the specified pieces with simple geometry conditions, the optimal knots ordinates and abscissas within the specified distribution ranges are obtained by employing sequential optimization method with the least square sense. In the examples it is proved that the new method works well by building various pump test data into smooth curves without disturbance caused by the random test error.