Quadcopter Tracking Using Euler-Angle-Free Flatness-Based Control

Quadcopter trajectory tracking control has been extensively investigated and implemented in the past. Available controls mostly use the Euler angle standards to describe the quadcopter's rotational kinematics and dynamics. As a result, the same rotation can be translated into different roll, pitch, and yaw angles because there are multiple Euler angle standards for the characterization of rotation in a 3-dimensional motion space. To address this issue, this paper will develop a flatness-based trajectory tracking control without using Euler angles. We assess and test the proposed control's performance in the Gazebo simulation environment and contrast its functionality with the existing Mellinger controller, which has been widely adopted by the robotics and unmanned aerial system (UAS) communities. Our simulations also show that, for both controllers, the main cause of loss of stability is not the theoretical domain of stability, but it is instead the inability of quadcopter rotors to provide negative thrust as is requested by controllers for aggressive trajectories.