Detection and removal of excess materials in aircraft wings using continuum robot end-effectors

Excess materials are left inside aircraft wings due to manual operation errors, and the removal of excess materials is very crucial. To increase removal efficiency, a continuum robot (CR) with a removal end-effector and a stereo camera is used to remove excess objects. The size and weight characteristics of excess materials in aircraft wings are analyzed. A novel negative pressure end-effector and a two-finger gripper are designed based on the CR. The negative pressure end-effector aims to remove nuts, small rivets, and small volumes of aluminum shavings. A two-finger gripper is designed to remove large volumes of aluminum shavings. A stereo camera is used to achieve automatic detection and localization of excess materials. Due to poor lighting conditions in the aircraft wing compartment, supplementary lighting devices are used to improve environmental lighting. Then, You Only Look Once (YOLO) v5 is used to classify and detect excess objects, and two training data sets of excess objects in two wings are constructed. Due to the limited texture features inside the aircraft wings, this paper adopts an image-matching method based on the results of YOLO v5 detection. This matching method avoids the performance instability problem based on Oriented Fast and Rotated BRIEF feature point matching. Experimental verification reveals that the detection accuracy of each type of excess exceeds 90%, and the visual localization error is less than 2 mm for four types of excess objects. Results show the two end-effectors can work well for the task of removing excess material from the aircraft wings using a CR.