The knot factor method and its applications in blade measurement

Blade measurement is a key technique and a hard nut to crack in aero-compressor manufacturing. This paper analyses the law of the knot vector's influence on NURBS interpolation curve, proposes a Knots Factor Method (KFM) to meet the needs of interpolation of the discrete points in blade measurement. Using the theoretic points and characteristic parameter, knot factors and mathematic models are constructed to fit the blade surface using the KFM. Based on the models and the discrete blade surface points, the blade characteristic parameter is evaluated. The results of the experiment show that the KFM is an effective method to fit the discrete points in blade measurement.