Large-scale offshore wind turbine blades need careful dimensional inspection at the production stage. This paper aims to establish an accurate measurement technique using Coherent Laser Radar technology combined with B-Spline point generation and alignment. Through varying the Degrees of Freedom (DoF), used for data point transformation, within the Spatial Analyser software package, erroneous inspection results generated by unconstrained blade flexing can be eradicated. The paper concludes that implementing a single B-Spline point generation and alignment method, whilst allowing transformation with DoF in X, Y and Rz, provides confidence to wind turbine blade manufacturers that inspection data is accurate. The experimental procedure described in this paper can also be applied to the precision inspection of other large-scale non-rigid, unconstrained objects. 
Investigating the measurement of offshore wind turbine blades using coherent laser radar