Analyzing 3D Limb Kinematics of Drosophila Melanogaster for Robotic Platform Development.

Recent work in insect-inspired robotics has highlighted the benefits of closely aligning the degrees of freedom (DoF) of a robotic platform with those of the target animal. However, to actualize this approach, the kinematics of the animal must be closely examined and balanced with considerations unique to a robotic counterpart. To inform the development of a robot inspired by Drosophila melanogaster, we collected 3D pose estimation data from the insect and analyzed the kinematics of the middle and hind limb pairs to find combinations of three DoF that best approximate animal motion. For our analysis, we simulated a baseline kinematic leg chain comprised of seven DoF for each frame of the motion capture data. We then fixed certain DoF and found a 'best fit' configuration relative to the animal. In these configurations, we analyzed the positional error of each joint's midpoints, as well as the angle of the leg plane from vertical. We found that using a three DoF combination of CTr elevation/depression, TrF pronation/supination, and FTi flexion/extension, we are able to closely approximate the motions of the insect while balancing necessary robotic platform considerations.