UV communication cooperative formation UAV alliance capture algorithm.

The capture of target unmanned aerial vehicles (UAVs) by a UAV formation is one of the important and typical tasks in multi-UAV battlefield operations. In this paper, an ultraviolet (UV) light communication-assisted formation UAV alliance capture algorithm is proposed, which combines UV light communication technology with a capture algorithm. With the help of wireless UV light to assist UAV formation inter-UAV data confidentiality transmission and non-line-of-sight communication, the algorithm integrates the alliance generation algorithm with the region minimization strategy, solves the optimal alliance structure by using the dynamic programming method, and implements the aerial capture of the target UAVs by using the region minimization strategy, so as to complete the task of efficiently capturing multi-targets by the UAV formation in complex scenarios. Simulation comparisons were conducted between the region minimization strategy and the proposed UV communication-assisted formation UAV alliance capture algorithm. The results show that the proposed algorithm reduces energy consumption by 12.73% on average and decreases the average number of algorithm iterations by 27.49% during the UAV formation capture of multiple targets, which verifies its low energy consumption and high capture efficiency.

Wireless ultraviolet cooperative unmanned aerial vehicle formation communication link maintenance method.

A stable formation communication network can improve the task efficiency of a unmanned aerial vehicle (UAV) cluster. Aiming at the topology construction of the UAV formation communication network, combined with the optimal rigid graph theory, we design a three-dimensional UAV formation communication network generation algorithm based on the optimal rigid graph. We construct a new link weight function by introducing node residual energy and communication path loss to reduce the overall energy consumption of formation. Aiming at the problem that the communication link of the UAV is interrupted when the formation network is moving, a UAV communication beam tracking and holding method based on a multiple-input multiple-output (MIMO) structure and position prediction is designed. Simulation results show that the network topology constructed by the UAV formation communication network generation algorithm has a good average node degree, and effectively improves the network connectivity and communication fault tolerance. Compared with the tracking and holding algorithm based on the received signal strength, the beam tracking and holding algorithm significantly reduces the number of link interruptions, and the communication success holding rate can be basically maintained at about 90%.

Research on the rapid assembly algorithm of the wireless ultraviolet cooperative UAV formation.

Aiming at the problem that the strong electromagnetic interference environment restricts the communication of the Unmanned Aerial Vehicle(UAV) formation, which affects the rapid assembly of the UAV formation, a wireless ultraviolet cooperative UAV formation rapid assembly algorithm is proposed to realize the fixed-point assembly of the UAV formation in the airspace. First, the Ultraviolet(UV) light beacon model is used to realize the information interaction of the UAV formation. secondly, the UV four-node positioning algorithm is used to realize the three-dimensional positioning of the UAV formation. Combined with the method, the UAV formation can reach a consensus speed when assembling. The simulation results show that when there are more than 6 reference nodes, the three-dimensional space positioning accuracy can reach 96%. The assembly algorithm can realize the fixed-point assembly of the UAV formation, and can maintain the circular motion trajectory after the assembly is completed.

Optimal path selection algorithm for UAV formation guided by a UV virtual fence.

This paper studies the optimal flight path selection problem of unmanned aerial vehicle (UAV) formations in multi-obstacle areas. According to the characteristics of wireless ultraviolet (UV) light communication conforming to the probability coverage model, a wireless UV light self-organizing network coverage model is proposed; the UV light of different wavelengths is divided into a detection area, communication area, and early warning area. A consensus algorithm with leaders and followers is designed, and an artificial potential field method is introduced to ensure that the UAV formation successfully avoids obstacles. Simulation results show that the UAV formation can choose a reasonable flight route under the improved algorithm, and the average obstacle avoidance time is reduced by 6.75 s compared with the original algorithm. Comparing the flight paths of formations in barrier-free and multi-obstacle environments, the obstacle avoidance range of UAVs is not more than 1 m. The UV light self-organizing coverage model can be applied to military communications and disaster relief.

Wireless ultraviolet scattering channel estimation method based on deep learning.

Due to the strong scattering characteristics, there are serious problems of inter-symbol interference (ISI) and transmission attenuation in the none-line-of-sight (NLOS) wireless ultraviolet communication system. In this paper, a wireless ultraviolet scattering channel estimation method based on deep learning is presented. The learning model structure is designed by combining the one-dimensional convolutional neural network (1D-CNN) and the deep neural network (DNN). In the training stage, the network optimization process is improved by the differential evolution (DE) algorithm. The computer simulation results show that the proposed deep learning channel estimation scheme has better mean square error (MSE) performance and bit error rate (BER) performance compared with the traditional algorithms. Furthermore, we verify the stability of this scheme in different communication environments, and the constructed neural network model has good generalization ability.

UAV assisted landing guided by UV LEDs.

Ultraviolet (UV) light communication has several advantages, including strong anti-interference ability, all-weather operation, and covert communications. In this paper, we built a landing assistance system for an unmanned aerial vehicle (UAV). In addition, we derived the formula of Lambertian power for UV LED. This formula is compared to the traditional line-of-sight (LOS) UV power formula in consideration of not only the area of the receiving aperture, but also the divergence angle of the UV LED. The simulation results show that with the increase of the receiver angle, the larger the divergence angle of the UV LED, the faster the UV power attenuation. When the receiver is not in the direction of the light source normal and the angle is fixed, there will be an optimal Lambertian order to make the receiver receive the maximum optical power at this angle. Finally, we did a set of outdoor experiments, which verified the correctness of the theoretical results.

Underwater wireless optical communication multi-tokens random backoff neighbor discovery method.

The cooperation of multiple pieces of equipment can greatly improve the efficiency of work when performing tasks underwater. Networking communication is a crucial technology for underwater cooperation. Wireless optical communication technology has many advantages in underwater networking communication. Neighbor discovery is a key part of networking between nodes, and it is required to establish links quickly. This paper combines the token mechanism with the random backoff mechanism and proposes a multi-tokens random backoff (MTRB) neighbor discovery method for underwater wireless optical communication. Simulation and analysis of the MTRB method show that the method has high neighbor discovery efficiency. When the parameters are selected properly, the rate of neighbor discovery by the MTRB method is increased by about 50% compared with the single token and the random backoff algorithm.

Research on pulse response characteristics of wireless ultraviolet communication in mobile scene.

Based on the Riemann sum method, we propose the idea of studying the pulse response width in a moving scene by using the non-line-of-sight (NLOS) wireless ultraviolet (UV) single-scatter communication model. We simulated the effect of the transmitter moving in eight directions from the origin on the pulse response width, when the receiver is fixed at point (100, 0, 0). Furthermore, the pulse response characteristics of the receiver were analyzed with varying elevation angle, beam angle, field-of-view (FOV) angle, and other geometric parameters. The results show that the pulse response width is widened under the condition of movement. In addition, the influence of the elevation angle of the transmitter on the pulse width is larger than that of the receiver. However, the effect of the FOV and beam angles on the pulse response width is not obvious when the FOV angle is large.

The Study of UV Scattering Polarization Properties of Spherical Particles of Haze.

With the rapid development of economy and society in our country, atmospheric haze has become a prominent environmental issue. Measuring haze particles is also important. Polarized ultraviolet light is scattered by atmospheric haze particles, the changes of scattered light polarization state(Stokes vector and the degree of polarization) in atmospheric haze can reflect the physical properties of the particles (particle size and the complex refractive index, etc.). Based on Mie scattering theory, line-of-sight and non-line-of-sight of a single UV scattering model is established. On one hand, the effects of the physical properties of the single and chain-structure spherical particles for the UV light polarization properties are studied. On the other hand, based on Monte Carlo Simulation, the impacts of haze particle concentration on polarization state at a fixed particle size distribution are discussed. The simulation results show that: with the particle size of single spherical increasing, the scattered light intensity in Stokes vector (Is) is significantly enhanced. Is shows a trend of first increase then decrease with the increase of the complex refractive index's imaginary part. The degree of polarization is constantly increasing with the increase of the complex refractive index's imaginary part and the imaginary part of the complex refractive index is small, the degree of polarization trend of fast increase. With the concentration of particles in haze increasing when the distribution of particle size is a fixed value, haze particles scattering coefficient, extinction coefficient and absorption coefficient showed a linear increase, while Is is reduced after the first increases. For chain-structure spherical particles, with the increase of the number of particles, Is shows a tendency to increase. As the same time, degrees of polarization distinguish whether the chain-structure spherical particles are made up by the same spherical particle. In the chain-structure consisted of same spherical particles, Is increases linearly with the increase of the number of particles and the degree of polarization does not change. The Is under the chain-structure consisted of different spherical particles can distinguish particles' physical properties according to the changing trend of scattering light polarization state.