Of traditional vibration displacement measurement methods, the indirect measurement method has its large error and low accuracy while the direct measurement method can achieve accuracy with high cost and poor utility. So a vibration displacement measurement method using machine vision is proposed. A motor-driven flexible arm is selected as the measurement object. A CCD camera is used to collect the motion image of the marker on the arm's manipulator. After the visual processing such as threshold segmentation and centroid detection, the vibration displacement information of the manipulator is obtained. An experimental platform is built to verify the method. The result is compared with the vibration displacements obtained by piezoelectric material measurement method and the simulation method. It is shown that the machine vision-based vibration displacement measurement method can be well applied to the flexible arm without any contacts. The accurate and real-time vibration displacement measurement of the arm is superior to the piezoelectric material measurement method, avoiding the influence of formula errors and other effects, and has obvious advantages.

vibration displacement  /  flexible arm  /  machine vision  /  piezoelectric material