Multi-body dynamics based on efficient wing morphing mechanism for eVTOL-UAV and experimental realization

Abstract

Wing morphing has attracted the researchers in recent days to develop variable aerodynamic configurations, to achieve all-terrain operational capabilities for eVTOL vehicles. The present paper deals with a variable wing motion using linear miniaturized actuators (LMAs), having a range of 200 N. A robotic gimbal mechanism is designed to realize a 3D rigid body wing morphing in pitch, yaw, and roll planes. The multi-body simulation results are validated through experiments, conducted on a test rig for a sweep of ±15°, pitch of ±12°, and roll of ±15°, respectively. The morphing mechanism is directly associated with the number of links, joints, and couplings, to achieve global kinematics from of 6-DOF. A simple 2D representations of the morphing mechanism is introduced, and the Denavit-Hartenberg (D-H) convention is adopted to assign frames to perform forward kinematics on a single-axis wing travel. Lagrangian mechanics and Euler- Lagrange equations are utilized to obtain the S-DOF wing equations of motion and the rotation matrices defines the multi-axis wing morphing in 3D space. Geometrical and Multi Body Dynamics analyses are performed to envisage the architecture of the rigid body mechanism of a UAV wing using Altair’s Motion Solve. Prismatic and Revolute joints are employed in the proposed assembly to form a L–shaped robotic coupling system and the LMAs of three numbers are transmitted and converted into rotary motions. Finally, the stress cleared morphing wing travel in 3D space is experimentally demonstrated for its functionality and reliability for real time implementation.