Adaptive Flight Stabilization Framework for a Planar 4R-Foldable Quadrotor: Utilizing Morphing to Navigate in Confined Environments

Abstract

A planar 4R-foldable quadrotor, i.e., foldable quadrotor with four independent revolute joints for wings rotation has the edge over conventional quadrotor in confined space navigation due to its morphing capability and multimodal behaviors. However, the morphing induced inertial and center of gravity variations cause attitude destabilization, which impedes the trajectory tracking efficiency and reduces the flight stability in confined environments. In this paper, we propose an adaptive flight stabilization framework for a planar 4R-foldable morphing quadrotor that comprises the adaptive control and geometric tracking control. The adaptive control laws are developed to estimate the morphing induced inertial and center of gravity variations with respect to the desired attitude dynamics. These adaptive laws are then used to develop the feedback component of geometric tracking control which improves the trajectory tracking efficiency. Together with the controller design, the boundness of the attitude tracking errors is proved. Moreover, the simulations were conducted to validate the effectiveness of the proposed control framework in confined environments. Initial results show that the adaptive stabilization framework is effective in attitude stabilization and enhancing the trajectory tracking performance of a planar 4R-foldable morphing quadrotor.