ANTENNA TRACKER DESIGN WITH A DISCRETE LYAPUNOV STABILITY BASED CONTROLLER FOR MINI UNMANNED AERIAL VEHICLES

Authors : Mehmet Işcan, Ali Ihsan Tas, Berkem Vural, Ali Burak Ozden, Cüneyt Yilmaz

Pages : 77-85

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Publication Date : 2022-07-20

Article Type : Research

Abstract :Communication systems have recently been very important in mini unmanned aerial vehicles (UAV), which include many research subjects. Directional antennas are generally used in communication systems, and they should continuously and efficiently follow the UAVs with minimal errors. For this purpose, an "Antenna Tracker” system, which is capable of real-time autonomous orientation based on GPS data from the UAV, was designed. In the beginning, the system’s 3-dimensional solid model was obtained in SOLIDWORKSTM and its dynamical model was made in MATLAB / SimulinkTM environment. For controlling the system, a discrete-time model-based computed torque proportional controller, which is the state-of-the-art innovation in this study, was designed in two axes, and then its simulation studies were conducted on the STM32 board. The simulation studies showed that controlling the pan and tilt axes is sufficient for effective tracking, and the presented antenna tracker system is suitable for use in mobile ground control stations (GCS). By using a short sampling time for the controller, stable and precise antenna tracking is accomplished for a given reference path. When a 0.5 Hz sinusoidal reference signal input which is the maximum speed for any antenna tracker was used as a sample reference track, ±0.3- and ±0.6-degrees position error of pan and tilt angles were obtained, respectively. The controller can easily satisfy a smooth tracking operation with high accuracy.
Keywords : lyapunov stability, mini UAVs, antenna trackers, discrete control