Tolerance zone constrained alignment method for turbine blade model

To align the measurement data of the investment casting turbine blade and its Computer Aided Design (CAD) model to unify the coordinate system for its geometric shape inspection, a tolerance zone constrained model alignment method was presented. The objective function of the constrained model alignment method was established by combining the tolerance zone constrained conditions and the objective function of the basic iterative closest point algorithm. Methods based on genetic algorithm were adopted to solve the constrained alignment objective function. Simulation data and real measurement data of the turbine blade were used to perform model alignment testing. The results showed that the number of the model alignment control point outside the predefined tolerance zone could be reduced obviously.