Partial-State Feedback Control and Trajectory Specification for a Propeller-Driven Fixed-wing Aircraft

The development of a control for a small RC Aircraft, a small Wilga 2000, is presented. The aircraft dynamics is modelled using Spatial Operator Algebra (SOA) that allows to write the Newton-Euler Dynamics equations as a single equation. The propeller, usually modelled by its angular momentum, in this work modelled using SOA and is considered as an independent dynamic body and its effects combined with those of the aircraft, using Newton's third law, linking the aircraft longitudinal and the lateral-directional models. The model includes the dynamics and the kinematics of the aircraft. For the attitude representation, quaternions are used; while for the control design modified Rodrigues parameters are used. The aircraft has four controls, therefore is an under-actuated system. A Lyapunov function is proposed to stabilize the attitude position and speed with the body longitudinal axis (x-axis) speed. The trajectory is specified in an additive way by a sequence of attitude and speed changes.