Flapping motion measurement of honeybee bilateral wings using four virtual structured-light sensors

A novel vision system was developed to measure the flapping motion of bilateral wings for free-flying honeybees. In the system, a geometrical optical unit, including two planar reflectors and one prism with two reflection planes,was used to image one high-speed CMOS camera into two virtual cameras. Four virtual structured-light sensors, formed by combining the two virtual cameras and two laser-sheet sources, were available to observe the flapping motion of honeybee bilateral wings. In addition, an opto-electronic attracting equipment was included to attract the free-flying honeybee and trigger the high-speed camera to capture the image sequences of the free-flying honeybee automatically. The deformation of the bilateral wings was reconstructed by the distorted light-lines projected on the surface of the wings. The measuring range of the vision system was about 25mm×20mm×20mm, and its measurement precision was smaller than 0.08mm. The kinematics parameters of the bilateral wings, such as flapping angle, lag angle, attack angle, torsion angle and camber deformation, were measured by the vision system. The virtual structured-light vision system with only one high-speed camera saves system cost, and avoids asynchronism of multiple cameras.