Turbine Blade Shape Evaluation by Color Trapezoidal Phase-shifting 3D Measurement Technique

摘要

The key for coded structured light 3D measurement technique in turbine blade shape evaluation is to improve measurement accuracy, and anti-interference capability and measurement speed are taken into account simultaneously. Color trapezoidal phase-shifting technique by combing grey trapezoidal phase-shifting method with RGB color space model is proposed, which only needs a color trapezoidal fringe pattern to carry out 3D measurements. Color coupling and imbalance problems are analyzed and Color calibration method based on Caspi illumine model is proposed, which improves the measurement accuracy and anti-jamming capability. Measurement system was established according to mathematic model. Experimental results show that error of measured standard plane is less than 0.18mm. Finally, the method for turbine blade molded lines evaluation was explored.