Analysis of Uneven Wear in Driving Mechanism of Flapping-Wing UAV

Driving mechanism is an important part of the flapping-wing UAV. However, in the flight experiments, the driving mechanism failed several times which led to unexpected flight interruptions. This was because that the uneven wear in the hinge of the connecting rod and the crank was significantly serious, which was the main problem affecting flight stability. To solve the above problem, a multi-body dynamic model with clearance hinge is established, considering that the hinge of the connecting rod and the crank has clearance. The bushing is divided into multiple sections along the circumference, and the distance from each section to the axis is parameterized. The contact-impact force model is established between the connecting rod and each section of the bushing. In addition, the concept of wear cycle is introduced, and the wear depths under different wear cycles are iteratively calculated based on the Archard’s wear model. Finally, by analyzing the contact stresses between each section of the bushing and the crank under different wear cycles, the law of uneven wear of the bushing is obtained. The wear model in this paper is estimated to provide guidance for the life prediction and optimization design of the flapping wing driving mechanism.