Composite control of anti-drone platform for stable tracking under disturbance

First, focused on the complex problem that a U-shaped tracking frame is unreachable to obtain the pointing angles of an unmanned aerial vehicle target, a novel coordinate transformation method is proposed in this paper. The fixed transformation relationship between the intermediate links is deduced by establishing a unified coordinate system, simplifying the algorithm conversion process, and saving computing resources and time. Furthermore, the accuracy of the proposed method has been verified in both aspects of theory and experiment. Then, in order to achieve smooth motion performance between target pointing strategy and stable tracking strategy, a mode switching method based on hysteresis intervals is developed. Compared with the traditional single-point threshold method, the switching method overcomes the high frequency jitter problem. The experimental results validate the consistency between practical effects and theoretical expectations. Finally, to improve the disturbance rejection performance of the platform, a composite control method integrating the information from the gyroscope and circular grating is proposed. The corresponding control scheme and the compensation principle are conceived and explained. The experimental results show the anti-interference performance of the proposed composite control method is five times that of the closed-loop method based on the gyroscope speed signal and two times that of the disturbance observer control method.