摘要
给出了扩展多阶多项式拟合公式及等效阶次和评定误差的算法,并利用Matlab编制了相应的拟合函数和计算函数。以此为工具,针对同一典型真实标定曲线,研究了5组28种拟合公式的拟合情况。研究表明,选用合适的正负阶次多项式拟合,可在减少计算复杂度的同时,降低拟合误差,增强拟合效果。在叶尖间隙标定精度小于0.01 mm、电压采集误差小于2.5 mV的情况下,±3阶多项式拟合为该系统标定曲线的最佳拟合方式。
Calculation methods of multi-order polynomial fitting, equivalent order and error estimation are given here and corresponding fitting and calculation functions are worked out by Matlab. Using these tools, 28 formulae from 5 types are selected and fitted into a same calibration curve. The research indicates that a selected positive-and-negative order polynomial fitting can have a better effect than other types of multi-or- der polynomial fittings, with less complexity and error. ±3 order polynomial fitting was proved to be the best way when tip clearance precision was less than 0.01 mm and voltage error is less than 2.5 inV.
出处
《燃气涡轮试验与研究》
北大核心
2012年第B12期17-20,共4页
Gas Turbine Experiment and Research
关键词
叶尖间隙测量系统
正负阶次多项式拟合
涡轮发动机
拟合效果评定
tip clearance measurement
positive-and-negative order polynomial fitting
turbine engine
assessment of fitting
