Collision Analysis of the Motor and Camera in Light and Small UAVs Based on Experiment and Simulation

Abstract

For unmanned aerial vehicles (UAVs), their motor and camera are rigid components that are most likely causing damage in the event of a collision. Therefore, in the research of UAVs collision simulation, establishing accurate motor and camera FE models is the key step. Kinetic material tests were conducted for 7075 aluminum alloy, and an accurate material model was obtained. A test of motor and camera strike on plates was developed, and the dynamic response of the plates was obtained to verify the numerical method of UAV motor and camera strike on plates. Based on these, accurate FE models of motor and camera were established. In addition, the motor and camera were divided into element models with different sizes, and the influence of element size on calculation accuracy and efficiency was investigated. It is indicated that when the average size of the motor grid is less than 1.25 mm and the average size of the camera grid is less than 1 mm, a good balance could be achieved between calculation accuracy and calculation efficiency. Through comprehensive consideration, a 1.25 mm and a 1 mm mesh model were selected for the motor and the camera, respectively, to establish their finite element model which was then employed in the simulation of motor and camera strike on plates. The simulation results showed that the strain-time curve peak of the aluminum plate impacted by the motor had an error of 9.5% with the experimental result and that by the camera had an error of 9.7% with the experimental result. At the same time, the influences of speed and collision angle were investigated. It is indicated that the greater collision angle of the motor, the smaller collision angle of the camera, and the greater impact speed of both cause greater damage to the aluminum plate. The FE modelling method and collision simulation method of motor and camera proposed in this paper can greatly save the resources for testing the UAV performance through the practical structural strength test, especially for light and small UAVs.