ABSTRACT
The objective of this paper is to investigate the application of the photogrammetric approach to measure the vibration of a research-scale wind turbine blade model. In order to control the excitation (rotation of the wind turbine blade), a motor was used to spin the blades at controlled angular velocities. Two cameras are set in front of the turbine to tape the video images. Through a sequence of stereo image pairs acquired by high speed camera, the images are studied. The camera we used is the BASLER acA2000-340km (2048x1088, 340FPS). Before taking the photos camera calibration was conducted which include lens distortion and skew factor is examined. To track the displacement of the motion target on the turbine blade, after loading the 3D calibration, the 3D positions are calculated by using a stereo triangulation technique. Then the displacement fields by image template matching can be calculated. Application of the technique to track the 3D motion of the rotating wind turbine blade is made. Comparison on the measured displacement field using the contact sensor and noncontact image-based data are made. Application of rodrigues’s rotation to the test data collectd from the rotation turbine blade to identify the pitch and yaw angles is also demonstrated.
