Improving Mission Completion Coping with Engine Failure Using Energy-Based Control Approach

In modern flight control systems, especially for unmanned aerial vehicles (UAVs) with one engine, it is critical to maintain stable and efficient control on the longitudinal axis in both nominal and emergency scenarios. Conventional autopilot architectures often maintain aircraft states, such as airspeed and altitude, through independent control loops. This structure can cause cross-interactions between these two controls, which can enhance the control performance, especially in maneuvers with high energy exchange. In contrast, the Total Energy Control System (TECS) technique offers an energy-based control approach that simultaneously manages the total energy of the aircraft and how this energy is distributed between the kinetic and potential components. In this study, conventional longitudinal autopilot functions and TECS are comparatively analyzed under different mission profiles on Deneysel Hava Aracı (DEHA), a small-scale jet-powered UAV platform. The scenarios include nominal level flights, and energy-intensive maneuvers, as well as critical failure conditions such as engine loss. The simulation results show that the TECS converges faster to the reference commands and generates a lesser usage of the control surface displacement and throttle lever arm. Especially, in engine failure scenarios, it is observed that the TECS generates a descent profile with an optimized glide slope and successfully performs glide slope tracking with less energy loss. This study demonstrates the positive impact of the energy-based control method on flight safety and performance. Also, highlights the advantages of the multi-input multi-output (MIMO) based TECS approach beyond the limitations of classical single-input output (SISO) structures, especially in emergency scenarios. This study indicates that the TECS is a powerful autopilot approach to complete the mission planning of guidance & navigation.