Research on automatic tracking system for directional antenna of UAV

In order to meet the requirements of communication of unmanned aerial vehicle (UAV) over a long distance, the ground directional antenna automatic tracking system has been developed with the UAV location information to guide. With the real-time acquisition directional antenna vehicle position, velocity, azimuth and elevation information, the directional antenna automatic tracking ability in motion is realized and it enhances the system mobility and concealment. The traditional methods to calculate the target angle using 2 points usually need the information of relative position of the 2 points. The relative position is difficult to be obtained in real time systems. Thus a novel method is presented in this paper. The proposed method does not need to consider the relative position of 2 points, which is more convenient in applications. When the directional antenna is moving with its loading vehicle, the GPS signal is easy to be disturbed, resulting in the loss of the target tracking. The tracking system has larger motor fluctuation and greater tracking error caused by the low update frequency of the UAV position. In order to overcome these shortcomings, UAV speed is adopted to predict the position in order to realize smooth angle tracking and solve the fluctuation, thus the tracking accuracy is improved. The hardware and software design of the control system is described in detail. Test results show that the developed directional antenna has motorized tracking capability and high tracking accuracy and it can meet the requirements of UAV control.