无人机定向天线自跟踪系统研究

为了满足无人机(UAV)远距离通信的需要,设计研制了以无人机位置信息为引导的地面定向天线自跟踪系统。基于实时获取定向天线载车位置、速度、方位和俯仰角等信息,实现了定向天线在运动中对目标进行自动跟踪的能力,提高了系统的机动性和隐蔽性。针对目前利用2点位置来计算目标角的方法存在需要通过相对位置才能确定实际目标角的不足,提出了一种不需要考虑2点相对位置就能直接计算出目标角的计算方法,为工程应用带来了方便。针对定向天线地面载车在机动时GPS信号容易受干扰,从而造成跟踪目标丢失,以及因无人机位置信息更新频率较低而造成的跟踪系统运动抖动、跟踪误差较大等问题,提出了一种基于速度对位置进行预测平滑的控制策略,有效解决了以上问题,并显著提高了跟踪精度。设计研制了定向天线自跟踪系统的软硬件,并进行了测试,结果表明:研制的定向天线具有机动跟踪能力和较高的跟踪精度,能满足无人机对定向天线自跟踪的需要。

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.