Communication Delay in UAV Missions: A Controller Gain Analysis to Improve Flight Stability

In real-world applications involving unmanned aerial vehicles (UAVs) the presence of communication delays can deteriorate the performance of flight control system or even cause instabilities. However, it is possible to improve the performance and ensure flight stability in the task execution by properly controlling the UAV considering the transport delay. This work analyzes the asymptotic convergence of a quadrotor, under time-delay in the communication with a ground control station. The effects of the communication delay, as well as the response-signal behavior of the quadrotors in the accomplishment of positioning missions are presented and analyzed by numerical simulations. The performance indexes (IAE and ITAE) assist the estimation of the acceptable time-delay limit. The results show that the adopted controller, without any adaptive tuning, can handle a delay of up to 1.2 seconds, which means a blind time of 40 packets of information. As expected, the longer the delay, the lower the gains. Consequently, as the delay increases, the quadrotor takes longer to accomplish the mission carefully and successfully.