No abstract

In this paper, a kind of antinarrowband interference intelligent method based on cognitive MIMO (multiple-input multiple-output) airspace, time domain, frequency domain, and code domain is proposed. This method combines perceptual technology, spread spectrum code, MIMO space-time coding, and so on. Through coordinating space, time, frequency, and code element diversity, the narrowband interference in the UAV (unmanned aerial vehicle) monitoring and control link is effectively countered. The input and output model of MIMO monitoring and control link of UAV with natural interference are described. Then, the realization principle of the multidomain antinarrowband interference method based on CR-MIMO is presented, and the corresponding models of receiving and transmitting are also given. Finally, the anti-interference performance of the proposed method is analyzed theoretically and validated through simulation experiments, and the effectiveness of the proposed method is verified.

Background: The positioning accuracy is the most important index of reconnaissance positioning system. The positioning accuracy involves many factors, such as the position, attitude and motion state of the flight platform, the pointing accuracy of the stable platform, and various coordinate transformations. The reasonable fusion strategy can guarantee the stable positioning accuracy, so it is very important to study the precise fusion of machine vision, 3D geographic data and UAV airborne positioning information, so as to realize the optimal combination of positioning data and complete the accurate and rapid positioning of the ground target. Methods: In the paper, it proposed a location model based on stereo vision and spatial information fusion method, it fully integrates visual information, satellite positioning information and spatial geographic information, greatly improve the accuracy of positioning, and through real-time processing algorithm, greatly improve the real-time positioning. Results: Through the related experiments, the accuracy of positioning and real-time ability of positioning can reach about two-three meters. Conclusion: The proposed real-time and high-precision positioning method of ground target through UAV stereo vision and spatial information fusion which is improved significantly compared with traditional methods.

Background: The MEMS scanning mirror prototype is a spatial scanning device, which has the characteristics of light mass, low drive voltage, large scanning and high angular measurement accuracy. Methods: The MEMS scanning mirror prototype uses the piezoelectric driving principle to drive the micro-structure to realize two-axis scanning. The corner of the MEMS scanning mirror is measured by using a piezoelectric resistance sensor. In the paper, it studies the damping properties of MEMS scanning mirrors, deduces the damping force formula of MEMS scanning mirrors, the influence of different sizes and structures of MEMS scanning mirrors on the damping force and the amplitude of scanning mirror angles are analyzed, and a structural optimization design method to reduce the driving voltage of MEMS scanning mirrors is proposed. Results: The theoretical analysis, design and testing of piezoelectric driven MEMS scanning microscopes are carried out. Conclusion: Through related experiments, it is verified that the maximum scanning range and the precision index of angle measurement meet the requirements of the index.