Noncontact measurement for rotational motion has advantages over the traditional method which measures rotational motion by\nmeans of installing some devices on the object, such as a rotary encoder. Cameras can be employed as remote monitoring or\ninspecting sensors to measure the angular velocity of a propeller because of their commonplace availability, simplicity, and\npotentially low cost. A defect of the measurement with cameras is to process the massive data generated by cameras. In order to\nreduce the collected data from the camera, a camera using ERS (electronic rolling shutter) is applied to measure angular\nvelocities which are higher than the speed of the camera. The effect of rolling shutter can induce geometric distortion in the\nimage, when the propeller rotates during capturing an image. In order to reveal the relationship between the angular velocity\nand the image distortion, a rotation model has been established. The proposed method was applied to measure the angular\nvelocities of the two-blade propeller and the multiblade propeller. The experimental results showed that this method could\ndetect the angular velocities which were higher than the camera speed, and the accuracy was acceptable.
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