Decoupled Lateral-Longitudinal Dynamic Modeling and Control of Unmanned Aerial Vehicles

Considering the amount of unmanned aerial vehicles (UAV) and the forthcoming new kinds of UAV’s, it is important to design a control strategy for different kinds of UAV’s tasks to provide a fast, robust, reliable, and accurate control approaches for trajectory tracking of any kind of UAVs. For these reasons, this paper is proposed a decoupled lateral-longitudinal control strategy for unmanned aerial vehicles. This research study begins with the dynamic model derivation of the separated unmanned aerial vehicle dynamics, this means, by separating the longitudinal dynamics and lateral dynamics. This objective is achieved by obtaining the longitudinal and lateral kinematics, and on this basis, the longitudinal dynamics are obtained by the linear coordinates in the longitudinal plane along with the pitch angle. Something similar is done to obtain the lateral kinematics in which the roll and yaw angle along with the linear displacement in y are obtained. For the lateral and longitudinal dynamics, derivation of two Lagrangians is derived for each case, and then by the Euler-Lagrange formulation, the respective dynamic models are obtained. The decoupled controller for the longitudinal and lateral dynamics is obtained first by providing an extra state variable that considers the errors between the desired roll, pitch, and yaw angle and the obtained angles, to provide the required actuator position and attitude. A numerical experiment is provided in which the desired reference profile is implemented. As it is corroborated, the action of the controller for the longitudinal and lateral dynamics in their respective loops drives the variables to the required final value.